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[official-gcc.git] / gcc / sched-int.h
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1 /* Instruction scheduling pass. This file contains definitions used
2 internally in the scheduler.
3 Copyright (C) 1992-2024 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
10 version.
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
21 #ifndef GCC_SCHED_INT_H
22 #define GCC_SCHED_INT_H
24 #ifdef INSN_SCHEDULING
26 /* Identificator of a scheduler pass. */
27 enum sched_pass_id_t { SCHED_PASS_UNKNOWN, SCHED_RGN_PASS, SCHED_EBB_PASS,
28 SCHED_SMS_PASS, SCHED_SEL_PASS };
30 /* The algorithm used to implement -fsched-pressure. */
31 enum sched_pressure_algorithm
33 SCHED_PRESSURE_NONE,
34 SCHED_PRESSURE_WEIGHTED,
35 SCHED_PRESSURE_MODEL
38 typedef vec<basic_block> bb_vec_t;
39 typedef vec<rtx_insn *> insn_vec_t;
40 typedef vec<rtx_insn *> rtx_vec_t;
42 extern void sched_init_bbs (void);
44 extern void sched_extend_luids (void);
45 extern void sched_init_insn_luid (rtx_insn *);
46 extern void sched_init_luids (const bb_vec_t &);
47 extern void sched_finish_luids (void);
49 extern void sched_extend_target (void);
51 extern void haifa_init_h_i_d (const bb_vec_t &);
52 extern void haifa_finish_h_i_d (void);
54 /* Hooks that are common to all the schedulers. */
55 struct common_sched_info_def
57 /* Called after blocks were rearranged due to movement of jump instruction.
58 The first parameter - index of basic block, in which jump currently is.
59 The second parameter - index of basic block, in which jump used
60 to be.
61 The third parameter - index of basic block, that follows the second
62 parameter. */
63 void (*fix_recovery_cfg) (int, int, int);
65 /* Called to notify frontend, that new basic block is being added.
66 The first parameter - new basic block.
67 The second parameter - block, after which new basic block is being added,
68 or the exit block, if recovery block is being added,
69 or NULL, if standalone block is being added. */
70 void (*add_block) (basic_block, basic_block);
72 /* Estimate number of insns in the basic block. */
73 int (*estimate_number_of_insns) (basic_block);
75 /* Given a non-insn (!INSN_P (x)) return
76 -1 - if this rtx don't need a luid.
77 0 - if it should have the same luid as the previous insn.
78 1 - if it needs a separate luid. */
79 int (*luid_for_non_insn) (rtx);
81 /* Scheduler pass identifier. It is preferably used in assertions. */
82 enum sched_pass_id_t sched_pass_id;
85 extern struct common_sched_info_def *common_sched_info;
87 extern const struct common_sched_info_def haifa_common_sched_info;
89 /* Return true if selective scheduling pass is working. */
90 inline bool
91 sel_sched_p (void)
93 return common_sched_info->sched_pass_id == SCHED_SEL_PASS;
96 /* Returns maximum priority that an insn was assigned to. */
97 extern int get_rgn_sched_max_insns_priority (void);
99 /* Increases effective priority for INSN by AMOUNT. */
100 extern void sel_add_to_insn_priority (rtx, int);
102 /* True if during selective scheduling we need to emulate some of haifa
103 scheduler behavior. */
104 extern int sched_emulate_haifa_p;
106 /* Mapping from INSN_UID to INSN_LUID. In the end all other per insn data
107 structures should be indexed by luid. */
108 extern vec<int> sched_luids;
109 #define INSN_LUID(INSN) (sched_luids[INSN_UID (INSN)])
110 #define LUID_BY_UID(UID) (sched_luids[UID])
112 #define SET_INSN_LUID(INSN, LUID) \
113 (sched_luids[INSN_UID (INSN)] = (LUID))
115 /* The highest INSN_LUID. */
116 extern int sched_max_luid;
118 extern int insn_luid (rtx);
120 /* This list holds ripped off notes from the current block. These notes will
121 be attached to the beginning of the block when its scheduling is
122 finished. */
123 extern rtx_insn *note_list;
125 extern void remove_notes (rtx_insn *, rtx_insn *);
126 extern rtx_insn *restore_other_notes (rtx_insn *, basic_block);
127 extern void sched_insns_init (rtx);
128 extern void sched_insns_finish (void);
130 extern void *xrecalloc (void *, size_t, size_t, size_t);
132 extern void reemit_notes (rtx_insn *);
134 /* Functions in haifa-sched.cc. */
135 extern int haifa_classify_insn (const_rtx);
137 /* Functions in sel-sched-ir.cc. */
138 extern void sel_find_rgns (void);
139 extern void sel_mark_hard_insn (rtx);
141 extern size_t dfa_state_size;
143 extern void advance_state (state_t);
145 extern void setup_sched_dump (void);
146 extern void sched_init (void);
147 extern void sched_finish (void);
149 extern bool sel_insn_is_speculation_check (rtx);
151 /* Describe the ready list of the scheduler.
152 VEC holds space enough for all insns in the current region. VECLEN
153 says how many exactly.
154 FIRST is the index of the element with the highest priority; i.e. the
155 last one in the ready list, since elements are ordered by ascending
156 priority.
157 N_READY determines how many insns are on the ready list.
158 N_DEBUG determines how many debug insns are on the ready list. */
159 struct ready_list
161 rtx_insn **vec;
162 int veclen;
163 int first;
164 int n_ready;
165 int n_debug;
168 extern signed char *ready_try;
169 extern struct ready_list ready;
171 extern int max_issue (struct ready_list *, int, state_t, bool, int *);
173 extern void ebb_compute_jump_reg_dependencies (rtx, regset);
175 extern edge find_fallthru_edge_from (basic_block);
177 extern void (* sched_init_only_bb) (basic_block, basic_block);
178 extern basic_block (* sched_split_block) (basic_block, rtx);
179 extern basic_block sched_split_block_1 (basic_block, rtx);
180 extern basic_block (* sched_create_empty_bb) (basic_block);
181 extern basic_block sched_create_empty_bb_1 (basic_block);
183 extern basic_block sched_create_recovery_block (basic_block *);
184 extern void sched_create_recovery_edges (basic_block, basic_block,
185 basic_block);
187 /* Pointer to data describing the current DFA state. */
188 extern state_t curr_state;
190 /* Type to represent status of a dependence. */
191 typedef unsigned int ds_t;
192 #define BITS_PER_DEP_STATUS HOST_BITS_PER_INT
194 /* Type to represent weakness of speculative dependence. */
195 typedef unsigned int dw_t;
197 extern enum reg_note ds_to_dk (ds_t);
198 extern ds_t dk_to_ds (enum reg_note);
200 /* Describe a dependency that can be broken by making a replacement
201 in one of the patterns. LOC is the location, ORIG and NEWVAL the
202 two alternative contents, and INSN the instruction that must be
203 changed. */
204 struct dep_replacement
206 rtx *loc;
207 rtx orig;
208 rtx newval;
209 rtx_insn *insn;
212 /* Information about the dependency. */
213 struct _dep
215 /* Producer. */
216 rtx_insn *pro;
218 /* Consumer. */
219 rtx_insn *con;
221 /* If nonnull, holds a pointer to information about how to break the
222 dependency by making a replacement in one of the insns. There is
223 only one such dependency for each insn that must be modified in
224 order to break such a dependency. */
225 struct dep_replacement *replace;
227 /* Dependency status. This field holds all dependency types and additional
228 information for speculative dependencies. */
229 ds_t status;
231 /* Dependency major type. This field is superseded by STATUS above.
232 Though, it is still in place because some targets use it. */
233 ENUM_BITFIELD(reg_note) type:6;
235 unsigned nonreg:1;
236 unsigned multiple:1;
238 /* Cached cost of the dependency. Make sure to update UNKNOWN_DEP_COST
239 when changing the size of this field. */
240 int cost:20;
242 unsigned unused:4;
245 #define UNKNOWN_DEP_COST ((int) ((unsigned int) -1 << 19))
247 typedef struct _dep dep_def;
248 typedef dep_def *dep_t;
250 #define DEP_PRO(D) ((D)->pro)
251 #define DEP_CON(D) ((D)->con)
252 #define DEP_TYPE(D) ((D)->type)
253 #define DEP_STATUS(D) ((D)->status)
254 #define DEP_COST(D) ((D)->cost)
255 #define DEP_NONREG(D) ((D)->nonreg)
256 #define DEP_MULTIPLE(D) ((D)->multiple)
257 #define DEP_REPLACE(D) ((D)->replace)
259 /* Functions to work with dep. */
261 extern void init_dep_1 (dep_t, rtx_insn *, rtx_insn *, enum reg_note, ds_t);
262 extern void init_dep (dep_t, rtx_insn *, rtx_insn *, enum reg_note);
264 extern void sd_debug_dep (dep_t);
266 /* Definition of this struct resides below. */
267 struct _dep_node;
268 typedef struct _dep_node *dep_node_t;
270 /* A link in the dependency list. This is essentially an equivalent of a
271 single {INSN, DEPS}_LIST rtx. */
272 struct _dep_link
274 /* Dep node with all the data. */
275 dep_node_t node;
277 /* Next link in the list. For the last one it is NULL. */
278 struct _dep_link *next;
280 /* Pointer to the next field of the previous link in the list.
281 For the first link this points to the deps_list->first.
283 With help of this field it is easy to remove and insert links to the
284 list. */
285 struct _dep_link **prev_nextp;
287 typedef struct _dep_link *dep_link_t;
289 #define DEP_LINK_NODE(N) ((N)->node)
290 #define DEP_LINK_NEXT(N) ((N)->next)
291 #define DEP_LINK_PREV_NEXTP(N) ((N)->prev_nextp)
293 /* Macros to work dep_link. For most usecases only part of the dependency
294 information is need. These macros conveniently provide that piece of
295 information. */
297 #define DEP_LINK_DEP(N) (DEP_NODE_DEP (DEP_LINK_NODE (N)))
298 #define DEP_LINK_PRO(N) (DEP_PRO (DEP_LINK_DEP (N)))
299 #define DEP_LINK_CON(N) (DEP_CON (DEP_LINK_DEP (N)))
300 #define DEP_LINK_TYPE(N) (DEP_TYPE (DEP_LINK_DEP (N)))
301 #define DEP_LINK_STATUS(N) (DEP_STATUS (DEP_LINK_DEP (N)))
303 /* A list of dep_links. */
304 struct _deps_list
306 /* First element. */
307 dep_link_t first;
309 /* Total number of elements in the list. */
310 int n_links;
312 typedef struct _deps_list *deps_list_t;
314 #define DEPS_LIST_FIRST(L) ((L)->first)
315 #define DEPS_LIST_N_LINKS(L) ((L)->n_links)
317 /* Suppose we have a dependence Y between insn pro1 and con1, where pro1 has
318 additional dependents con0 and con2, and con1 is dependent on additional
319 insns pro0 and pro1:
321 .con0 pro0
322 . ^ |
323 . | |
324 . | |
325 . X A
326 . | |
327 . | |
328 . | V
329 .pro1--Y-->con1
330 . | ^
331 . | |
332 . | |
333 . Z B
334 . | |
335 . | |
336 . V |
337 .con2 pro2
339 This is represented using a "dep_node" for each dependence arc, which are
340 connected as follows (diagram is centered around Y which is fully shown;
341 other dep_nodes shown partially):
343 . +------------+ +--------------+ +------------+
344 . : dep_node X : | dep_node Y | : dep_node Z :
345 . : : | | : :
346 . : : | | : :
347 . : forw : | forw | : forw :
348 . : +--------+ : | +--------+ | : +--------+ :
349 forw_deps : |dep_link| : | |dep_link| | : |dep_link| :
350 +-----+ : | +----+ | : | | +----+ | | : | +----+ | :
351 |first|----->| |next|-+------+->| |next|-+--+----->| |next|-+--->NULL
352 +-----+ : | +----+ | : | | +----+ | | : | +----+ | :
353 . ^ ^ : | ^ | : | | ^ | | : | | :
354 . | | : | | | : | | | | | : | | :
355 . | +--<----+--+ +--+---<--+--+--+ +--+--+--<---+--+ | :
356 . | : | | | : | | | | | : | | | :
357 . | : | +----+ | : | | +----+ | | : | +----+ | :
358 . | : | |prev| | : | | |prev| | | : | |prev| | :
359 . | : | |next| | : | | |next| | | : | |next| | :
360 . | : | +----+ | : | | +----+ | | : | +----+ | :
361 . | : | | :<-+ | | | |<-+ : | | :<-+
362 . | : | +----+ | : | | | +----+ | | | : | +----+ | : |
363 . | : | |node|-+----+ | | |node|-+--+--+ : | |node|-+----+
364 . | : | +----+ | : | | +----+ | | : | +----+ | :
365 . | : | | : | | | | : | | :
366 . | : +--------+ : | +--------+ | : +--------+ :
367 . | : : | | : :
368 . | : SAME pro1 : | +--------+ | : SAME pro1 :
369 . | : DIFF con0 : | |dep | | : DIFF con2 :
370 . | : : | | | | : :
371 . | | | +----+ | |
372 .RTX<------------------------+--+-|pro1| | |
373 .pro1 | | +----+ | |
374 . | | | |
375 . | | +----+ | |
376 .RTX<------------------------+--+-|con1| | |
377 .con1 | | +----+ | |
378 . | | | | |
379 . | | | +----+ | |
380 . | | | |kind| | |
381 . | | | +----+ | |
382 . | : : | | |stat| | | : :
383 . | : DIFF pro0 : | | +----+ | | : DIFF pro2 :
384 . | : SAME con1 : | | | | : SAME con1 :
385 . | : : | +--------+ | : :
386 . | : : | | : :
387 . | : back : | back | : back :
388 . v : +--------+ : | +--------+ | : +--------+ :
389 back_deps : |dep_link| : | |dep_link| | : |dep_link| :
390 +-----+ : | +----+ | : | | +----+ | | : | +----+ | :
391 |first|----->| |next|-+------+->| |next|-+--+----->| |next|-+--->NULL
392 +-----+ : | +----+ | : | | +----+ | | : | +----+ | :
393 . ^ : | ^ | : | | ^ | | : | | :
394 . | : | | | : | | | | | : | | :
395 . +--<----+--+ +--+---<--+--+--+ +--+--+--<---+--+ | :
396 . : | | | : | | | | | : | | | :
397 . : | +----+ | : | | +----+ | | : | +----+ | :
398 . : | |prev| | : | | |prev| | | : | |prev| | :
399 . : | |next| | : | | |next| | | : | |next| | :
400 . : | +----+ | : | | +----+ | | : | +----+ | :
401 . : | | :<-+ | | | |<-+ : | | :<-+
402 . : | +----+ | : | | | +----+ | | | : | +----+ | : |
403 . : | |node|-+----+ | | |node|-+--+--+ : | |node|-+----+
404 . : | +----+ | : | | +----+ | | : | +----+ | :
405 . : | | : | | | | : | | :
406 . : +--------+ : | +--------+ | : +--------+ :
407 . : : | | : :
408 . : dep_node A : | dep_node Y | : dep_node B :
409 . +------------+ +--------------+ +------------+
412 struct _dep_node
414 /* Backward link. */
415 struct _dep_link back;
417 /* The dep. */
418 struct _dep dep;
420 /* Forward link. */
421 struct _dep_link forw;
424 #define DEP_NODE_BACK(N) (&(N)->back)
425 #define DEP_NODE_DEP(N) (&(N)->dep)
426 #define DEP_NODE_FORW(N) (&(N)->forw)
428 /* The following enumeration values tell us what dependencies we
429 should use to implement the barrier. We use true-dependencies for
430 TRUE_BARRIER and anti-dependencies for MOVE_BARRIER. */
431 enum reg_pending_barrier_mode
433 NOT_A_BARRIER = 0,
434 MOVE_BARRIER,
435 TRUE_BARRIER
438 /* Whether a register movement is associated with a call. */
439 enum post_call_group
441 not_post_call,
442 post_call,
443 post_call_initial
446 /* Insns which affect pseudo-registers. */
447 struct deps_reg
449 rtx_insn_list *uses;
450 rtx_insn_list *sets;
451 rtx_insn_list *implicit_sets;
452 rtx_insn_list *control_uses;
453 rtx_insn_list *clobbers;
454 int uses_length;
455 int clobbers_length;
458 /* Describe state of dependencies used during sched_analyze phase. */
459 class deps_desc
461 public:
462 /* The *_insns and *_mems are paired lists. Each pending memory operation
463 will have a pointer to the MEM rtx on one list and a pointer to the
464 containing insn on the other list in the same place in the list. */
466 /* We can't use add_dependence like the old code did, because a single insn
467 may have multiple memory accesses, and hence needs to be on the list
468 once for each memory access. Add_dependence won't let you add an insn
469 to a list more than once. */
471 /* An INSN_LIST containing all insns with pending read operations. */
472 rtx_insn_list *pending_read_insns;
474 /* An EXPR_LIST containing all MEM rtx's which are pending reads. The list
475 can contain stack pointer instead of memory. This is a special case (see
476 sched-deps.cc::sched_analyze_1). */
477 rtx_expr_list *pending_read_mems;
479 /* An INSN_LIST containing all insns with pending write operations. */
480 rtx_insn_list *pending_write_insns;
482 /* An EXPR_LIST containing all MEM rtx's which are pending writes. */
483 rtx_expr_list *pending_write_mems;
485 /* An INSN_LIST containing all jump insns. */
486 rtx_insn_list *pending_jump_insns;
488 /* We must prevent the above lists from ever growing too large since
489 the number of dependencies produced is at least O(N*N),
490 and execution time is at least O(4*N*N), as a function of the
491 length of these pending lists. */
493 /* Indicates the length of the pending_read list. */
494 int pending_read_list_length;
496 /* Indicates the length of the pending_write list. */
497 int pending_write_list_length;
499 /* Length of the pending memory flush list plus the length of the pending
500 jump insn list. Large functions with no calls may build up extremely
501 large lists. */
502 int pending_flush_length;
504 /* The last insn upon which all memory references must depend.
505 This is an insn which flushed the pending lists, creating a dependency
506 between it and all previously pending memory references. This creates
507 a barrier (or a checkpoint) which no memory reference is allowed to cross.
509 This includes all non constant CALL_INSNs. When we do interprocedural
510 alias analysis, this restriction can be relaxed.
511 This may also be an INSN that writes memory if the pending lists grow
512 too large. */
513 rtx_insn_list *last_pending_memory_flush;
515 /* A list of the last function calls we have seen. We use a list to
516 represent last function calls from multiple predecessor blocks.
517 Used to prevent register lifetimes from expanding unnecessarily. */
518 rtx_insn_list *last_function_call;
520 /* A list of the last function calls that may not return normally
521 we have seen. We use a list to represent last function calls from
522 multiple predecessor blocks. Used to prevent moving trapping insns
523 across such calls. */
524 rtx_insn_list *last_function_call_may_noreturn;
526 /* A list of insns which use a pseudo register that does not already
527 cross a call. We create dependencies between each of those insn
528 and the next call insn, to ensure that they won't cross a call after
529 scheduling is done. */
530 rtx_insn_list *sched_before_next_call;
532 /* Similarly, a list of insns which should not cross a branch. */
533 rtx_insn_list *sched_before_next_jump;
535 /* Used to keep post-call pseudo/hard reg movements together with
536 the call. */
537 enum post_call_group in_post_call_group_p;
539 /* The last debug insn we've seen. */
540 rtx_insn *last_debug_insn;
542 /* The last insn bearing REG_ARGS_SIZE that we've seen. */
543 rtx_insn *last_args_size;
545 /* A list of all prologue insns we have seen without intervening epilogue
546 insns, and one of all epilogue insns we have seen without intervening
547 prologue insns. This is used to prevent mixing prologue and epilogue
548 insns. See PR78029. */
549 rtx_insn_list *last_prologue;
550 rtx_insn_list *last_epilogue;
552 /* Whether the last *logue insn was an epilogue insn or a prologue insn
553 instead. */
554 bool last_logue_was_epilogue;
556 /* The maximum register number for the following arrays. Before reload
557 this is max_reg_num; after reload it is FIRST_PSEUDO_REGISTER. */
558 int max_reg;
560 /* Element N is the next insn that sets (hard or pseudo) register
561 N within the current basic block; or zero, if there is no
562 such insn. Needed for new registers which may be introduced
563 by splitting insns. */
564 struct deps_reg *reg_last;
566 /* Element N is set for each register that has any nonzero element
567 in reg_last[N].{uses,sets,clobbers}. */
568 regset_head reg_last_in_use;
570 /* Shows the last value of reg_pending_barrier associated with the insn. */
571 enum reg_pending_barrier_mode last_reg_pending_barrier;
573 /* True when this context should be treated as a readonly by
574 the analysis. */
575 BOOL_BITFIELD readonly : 1;
578 typedef class deps_desc *deps_t;
580 /* This structure holds some state of the current scheduling pass, and
581 contains some function pointers that abstract out some of the non-generic
582 functionality from functions such as schedule_block or schedule_insn.
583 There is one global variable, current_sched_info, which points to the
584 sched_info structure currently in use. */
585 struct haifa_sched_info
587 /* Add all insns that are initially ready to the ready list. Called once
588 before scheduling a set of insns. */
589 void (*init_ready_list) (void);
590 /* Called after taking an insn from the ready list. Returns true if
591 this insn can be scheduled, false if we should silently discard it. */
592 bool (*can_schedule_ready_p) (rtx_insn *);
593 /* Return true if there are more insns that should be scheduled. */
594 bool (*schedule_more_p) (void);
595 /* Called after an insn has all its hard dependencies resolved.
596 Adjusts status of instruction (which is passed through second parameter)
597 to indicate if instruction should be moved to the ready list or the
598 queue, or if it should silently discard it (until next resolved
599 dependence). */
600 ds_t (*new_ready) (rtx_insn *, ds_t);
601 /* Compare priority of two insns. Return a positive number if the second
602 insn is to be preferred for scheduling, and a negative one if the first
603 is to be preferred. Zero if they are equally good. */
604 int (*rank) (rtx_insn *, rtx_insn *);
605 /* Return a string that contains the insn uid and optionally anything else
606 necessary to identify this insn in an output. It's valid to use a
607 static buffer for this. The ALIGNED parameter should cause the string
608 to be formatted so that multiple output lines will line up nicely. */
609 const char *(*print_insn) (const rtx_insn *, int);
610 /* Return true if an insn should be included in priority
611 calculations. */
612 bool (*contributes_to_priority) (rtx_insn *, rtx_insn *);
614 /* Return true if scheduling insn (passed as the parameter) will trigger
615 finish of scheduling current block. */
616 bool (*insn_finishes_block_p) (rtx_insn *);
618 /* The boundaries of the set of insns to be scheduled. */
619 rtx_insn *prev_head, *next_tail;
621 /* Filled in after the schedule is finished; the first and last scheduled
622 insns. */
623 rtx_insn *head, *tail;
625 /* If nonzero, enables an additional sanity check in schedule_block. */
626 unsigned int queue_must_finish_empty:1;
628 /* Maximum priority that has been assigned to an insn. */
629 int sched_max_insns_priority;
631 /* Hooks to support speculative scheduling. */
633 /* Called to notify frontend that instruction is being added (second
634 parameter == 0) or removed (second parameter == 1). */
635 void (*add_remove_insn) (rtx_insn *, int);
637 /* Called to notify the frontend that instruction INSN is being
638 scheduled. */
639 void (*begin_schedule_ready) (rtx_insn *insn);
641 /* Called to notify the frontend that an instruction INSN is about to be
642 moved to its correct place in the final schedule. This is done for all
643 insns in order of the schedule. LAST indicates the last scheduled
644 instruction. */
645 void (*begin_move_insn) (rtx_insn *insn, rtx_insn *last);
647 /* If the second parameter is not NULL, return nonnull value, if the
648 basic block should be advanced.
649 If the second parameter is NULL, return the next basic block in EBB.
650 The first parameter is the current basic block in EBB. */
651 basic_block (*advance_target_bb) (basic_block, rtx_insn *);
653 /* Allocate memory, store the frontend scheduler state in it, and
654 return it. */
655 void *(*save_state) (void);
656 /* Restore frontend scheduler state from the argument, and free the
657 memory. */
658 void (*restore_state) (void *);
660 /* ??? FIXME: should use straight bitfields inside sched_info instead of
661 this flag field. */
662 unsigned int flags;
665 /* This structure holds description of the properties for speculative
666 scheduling. */
667 struct spec_info_def
669 /* Holds types of allowed speculations: BEGIN_{DATA|CONTROL},
670 BE_IN_{DATA_CONTROL}. */
671 int mask;
673 /* A dump file for additional information on speculative scheduling. */
674 FILE *dump;
676 /* Minimal cumulative weakness of speculative instruction's
677 dependencies, so that insn will be scheduled. */
678 dw_t data_weakness_cutoff;
680 /* Minimal usefulness of speculative instruction to be considered for
681 scheduling. */
682 int control_weakness_cutoff;
684 /* Flags from the enum SPEC_SCHED_FLAGS. */
685 int flags;
687 typedef struct spec_info_def *spec_info_t;
689 extern spec_info_t spec_info;
691 extern struct haifa_sched_info *current_sched_info;
693 /* Do register pressure sensitive insn scheduling if the flag is set
694 up. */
695 extern enum sched_pressure_algorithm sched_pressure;
697 /* Map regno -> its pressure class. The map defined only when
698 SCHED_PRESSURE_P is true. */
699 extern enum reg_class *sched_regno_pressure_class;
701 /* Indexed by INSN_UID, the collection of all data associated with
702 a single instruction. */
704 struct _haifa_deps_insn_data
706 /* The number of incoming edges in the forward dependency graph.
707 As scheduling proceeds, counts are decreased. An insn moves to
708 the ready queue when its counter reaches zero. */
709 int dep_count;
711 /* Nonzero if instruction has internal dependence
712 (e.g. add_dependence was invoked with (insn == elem)). */
713 unsigned int has_internal_dep;
715 /* NB: We can't place 'struct _deps_list' here instead of deps_list_t into
716 h_i_d because when h_i_d extends, addresses of the deps_list->first
717 change without updating deps_list->first->next->prev_nextp. Thus
718 BACK_DEPS and RESOLVED_BACK_DEPS are allocated on the heap and FORW_DEPS
719 list is allocated on the obstack. */
721 /* A list of hard backward dependencies. The insn is a consumer of all the
722 deps mentioned here. */
723 deps_list_t hard_back_deps;
725 /* A list of speculative (weak) dependencies. The insn is a consumer of all
726 the deps mentioned here. */
727 deps_list_t spec_back_deps;
729 /* A list of insns which depend on the instruction. Unlike 'back_deps',
730 it represents forward dependencies. */
731 deps_list_t forw_deps;
733 /* A list of scheduled producers of the instruction. Links are being moved
734 from 'back_deps' to 'resolved_back_deps' while scheduling. */
735 deps_list_t resolved_back_deps;
737 /* A list of scheduled consumers of the instruction. Links are being moved
738 from 'forw_deps' to 'resolved_forw_deps' while scheduling to fasten the
739 search in 'forw_deps'. */
740 deps_list_t resolved_forw_deps;
742 /* If the insn is conditional (either through COND_EXEC, or because
743 it is a conditional branch), this records the condition. NULL
744 for insns that haven't been seen yet or don't have a condition;
745 const_true_rtx to mark an insn without a condition, or with a
746 condition that has been clobbered by a subsequent insn. */
747 rtx cond;
749 /* For a conditional insn, a list of insns that could set the condition
750 register. Used when generating control dependencies. */
751 rtx_insn_list *cond_deps;
753 /* True if the condition in 'cond' should be reversed to get the actual
754 condition. */
755 unsigned int reverse_cond : 1;
757 /* Some insns (e.g. call) are not allowed to move across blocks. */
758 unsigned int cant_move : 1;
762 /* Bits used for storing values of the fields in the following
763 structure. */
764 #define INCREASE_BITS 8
766 /* The structure describes how the corresponding insn increases the
767 register pressure for each pressure class. */
768 struct reg_pressure_data
770 /* Pressure increase for given class because of clobber. */
771 unsigned int clobber_increase : INCREASE_BITS;
772 /* Increase in register pressure for given class because of register
773 sets. */
774 unsigned int set_increase : INCREASE_BITS;
775 /* Pressure increase for given class because of unused register
776 set. */
777 unsigned int unused_set_increase : INCREASE_BITS;
778 /* Pressure change: #sets - #deaths. */
779 int change : INCREASE_BITS;
782 /* The following structure describes usage of registers by insns. */
783 struct reg_use_data
785 /* Regno used in the insn. */
786 int regno;
787 /* Insn using the regno. */
788 rtx_insn *insn;
789 /* Cyclic list of elements with the same regno. */
790 struct reg_use_data *next_regno_use;
791 /* List of elements with the same insn. */
792 struct reg_use_data *next_insn_use;
795 /* The following structure describes used sets of registers by insns.
796 Registers are pseudos whose pressure class is not NO_REGS or hard
797 registers available for allocations. */
798 struct reg_set_data
800 /* Regno used in the insn. */
801 int regno;
802 /* Insn setting the regno. */
803 rtx insn;
804 /* List of elements with the same insn. */
805 struct reg_set_data *next_insn_set;
808 enum autopref_multipass_data_status {
809 /* Entry is irrelevant for auto-prefetcher. */
810 AUTOPREF_MULTIPASS_DATA_IRRELEVANT = -2,
811 /* Entry is uninitialized. */
812 AUTOPREF_MULTIPASS_DATA_UNINITIALIZED = -1,
813 /* Entry is relevant for auto-prefetcher and insn can be delayed
814 to allow another insn through. */
815 AUTOPREF_MULTIPASS_DATA_NORMAL = 0,
816 /* Entry is relevant for auto-prefetcher, but insn should not be
817 delayed as that will break scheduling. */
818 AUTOPREF_MULTIPASS_DATA_DONT_DELAY = 1
821 /* Data for modeling cache auto-prefetcher. */
822 struct autopref_multipass_data_
824 /* Base part of memory address. */
825 rtx base;
827 /* Memory offsets from the base. */
828 int offset;
830 /* Entry status. */
831 enum autopref_multipass_data_status status;
833 typedef struct autopref_multipass_data_ autopref_multipass_data_def;
834 typedef autopref_multipass_data_def *autopref_multipass_data_t;
836 struct _haifa_insn_data
838 /* We can't place 'struct _deps_list' into h_i_d instead of deps_list_t
839 because when h_i_d extends, addresses of the deps_list->first
840 change without updating deps_list->first->next->prev_nextp. */
842 /* Logical uid gives the original ordering of the insns. */
843 int luid;
845 /* A priority for each insn. */
846 int priority;
848 /* The fusion priority for each insn. */
849 int fusion_priority;
851 /* The minimum clock tick at which the insn becomes ready. This is
852 used to note timing constraints for the insns in the pending list. */
853 int tick;
855 /* For insns that are scheduled at a fixed difference from another,
856 this records the tick in which they must be ready. */
857 int exact_tick;
859 /* INTER_TICK is used to adjust INSN_TICKs of instructions from the
860 subsequent blocks in a region. */
861 int inter_tick;
863 /* Used temporarily to estimate an INSN_TICK value for an insn given
864 current knowledge. */
865 int tick_estimate;
867 /* See comment on QUEUE_INDEX macro in haifa-sched.cc. */
868 int queue_index;
870 short cost;
872 /* '> 0' if priority is valid,
873 '== 0' if priority was not yet computed,
874 '< 0' if priority in invalid and should be recomputed. */
875 signed char priority_status;
877 /* Set if there's DEF-USE dependence between some speculatively
878 moved load insn and this one. */
879 unsigned int fed_by_spec_load : 1;
880 unsigned int is_load_insn : 1;
881 /* Nonzero if this insn has negative-cost forward dependencies against
882 an already scheduled insn. */
883 unsigned int feeds_backtrack_insn : 1;
885 /* Nonzero if this insn is a shadow of another, scheduled after a fixed
886 delay. We only emit shadows at the end of a cycle, with no other
887 real insns following them. */
888 unsigned int shadow_p : 1;
890 /* Used internally in unschedule_insns_until to mark insns that must have
891 their TODO_SPEC recomputed. */
892 unsigned int must_recompute_spec : 1;
894 /* What speculations are necessary to apply to schedule the instruction. */
895 ds_t todo_spec;
897 /* What speculations were already applied. */
898 ds_t done_spec;
900 /* What speculations are checked by this instruction. */
901 ds_t check_spec;
903 /* Recovery block for speculation checks. */
904 basic_block recovery_block;
906 /* Original pattern of the instruction. */
907 rtx orig_pat;
909 /* For insns with DEP_CONTROL dependencies, the predicated pattern if it
910 was ever successfully constructed. */
911 rtx predicated_pat;
913 /* The following array contains info how the insn increases register
914 pressure. There is an element for each cover class of pseudos
915 referenced in insns. */
916 struct reg_pressure_data *reg_pressure;
917 /* The following array contains maximal reg pressure between last
918 scheduled insn and given insn. There is an element for each
919 pressure class of pseudos referenced in insns. This info updated
920 after scheduling each insn for each insn between the two
921 mentioned insns. */
922 int *max_reg_pressure;
923 /* The following list contains info about used pseudos and hard
924 registers available for allocation. */
925 struct reg_use_data *reg_use_list;
926 /* The following list contains info about set pseudos and hard
927 registers available for allocation. */
928 struct reg_set_data *reg_set_list;
929 /* Info about how scheduling the insn changes cost of register
930 pressure excess (between source and target). */
931 int reg_pressure_excess_cost_change;
932 int model_index;
934 /* Original order of insns in the ready list. */
935 int rfs_debug_orig_order;
937 /* The deciding reason for INSN's place in the ready list. */
938 int last_rfs_win;
940 /* Two entries for cache auto-prefetcher model: one for mem reads,
941 and one for mem writes. */
942 autopref_multipass_data_def autopref_multipass_data[2];
945 typedef struct _haifa_insn_data haifa_insn_data_def;
946 typedef haifa_insn_data_def *haifa_insn_data_t;
949 extern vec<haifa_insn_data_def> h_i_d;
951 #define HID(INSN) (&h_i_d[INSN_UID (INSN)])
953 /* Accessor macros for h_i_d. There are more in haifa-sched.cc and
954 sched-rgn.cc. */
955 #define INSN_PRIORITY(INSN) (HID (INSN)->priority)
956 #define INSN_FUSION_PRIORITY(INSN) (HID (INSN)->fusion_priority)
957 #define INSN_REG_PRESSURE(INSN) (HID (INSN)->reg_pressure)
958 #define INSN_MAX_REG_PRESSURE(INSN) (HID (INSN)->max_reg_pressure)
959 #define INSN_REG_USE_LIST(INSN) (HID (INSN)->reg_use_list)
960 #define INSN_REG_SET_LIST(INSN) (HID (INSN)->reg_set_list)
961 #define INSN_REG_PRESSURE_EXCESS_COST_CHANGE(INSN) \
962 (HID (INSN)->reg_pressure_excess_cost_change)
963 #define INSN_PRIORITY_STATUS(INSN) (HID (INSN)->priority_status)
964 #define INSN_MODEL_INDEX(INSN) (HID (INSN)->model_index)
965 #define INSN_AUTOPREF_MULTIPASS_DATA(INSN) \
966 (HID (INSN)->autopref_multipass_data)
968 typedef struct _haifa_deps_insn_data haifa_deps_insn_data_def;
969 typedef haifa_deps_insn_data_def *haifa_deps_insn_data_t;
972 extern vec<haifa_deps_insn_data_def> h_d_i_d;
974 #define HDID(INSN) (&h_d_i_d[INSN_LUID (INSN)])
975 #define INSN_DEP_COUNT(INSN) (HDID (INSN)->dep_count)
976 #define HAS_INTERNAL_DEP(INSN) (HDID (INSN)->has_internal_dep)
977 #define INSN_FORW_DEPS(INSN) (HDID (INSN)->forw_deps)
978 #define INSN_RESOLVED_BACK_DEPS(INSN) (HDID (INSN)->resolved_back_deps)
979 #define INSN_RESOLVED_FORW_DEPS(INSN) (HDID (INSN)->resolved_forw_deps)
980 #define INSN_HARD_BACK_DEPS(INSN) (HDID (INSN)->hard_back_deps)
981 #define INSN_SPEC_BACK_DEPS(INSN) (HDID (INSN)->spec_back_deps)
982 #define INSN_CACHED_COND(INSN) (HDID (INSN)->cond)
983 #define INSN_REVERSE_COND(INSN) (HDID (INSN)->reverse_cond)
984 #define INSN_COND_DEPS(INSN) (HDID (INSN)->cond_deps)
985 #define CANT_MOVE(INSN) (HDID (INSN)->cant_move)
986 #define CANT_MOVE_BY_LUID(LUID) (h_d_i_d[LUID].cant_move)
989 #define INSN_PRIORITY(INSN) (HID (INSN)->priority)
990 #define INSN_PRIORITY_STATUS(INSN) (HID (INSN)->priority_status)
991 #define INSN_PRIORITY_KNOWN(INSN) (INSN_PRIORITY_STATUS (INSN) > 0)
992 #define TODO_SPEC(INSN) (HID (INSN)->todo_spec)
993 #define DONE_SPEC(INSN) (HID (INSN)->done_spec)
994 #define CHECK_SPEC(INSN) (HID (INSN)->check_spec)
995 #define RECOVERY_BLOCK(INSN) (HID (INSN)->recovery_block)
996 #define ORIG_PAT(INSN) (HID (INSN)->orig_pat)
997 #define PREDICATED_PAT(INSN) (HID (INSN)->predicated_pat)
999 /* INSN is either a simple or a branchy speculation check. */
1000 #define IS_SPECULATION_CHECK_P(INSN) \
1001 (sel_sched_p () ? sel_insn_is_speculation_check (INSN) : RECOVERY_BLOCK (INSN) != NULL)
1003 /* INSN is a speculation check that will simply reexecute the speculatively
1004 scheduled instruction if the speculation fails. */
1005 #define IS_SPECULATION_SIMPLE_CHECK_P(INSN) \
1006 (RECOVERY_BLOCK (INSN) == EXIT_BLOCK_PTR_FOR_FN (cfun))
1008 /* INSN is a speculation check that will branch to RECOVERY_BLOCK if the
1009 speculation fails. Insns in that block will reexecute the speculatively
1010 scheduled code and then will return immediately after INSN thus preserving
1011 semantics of the program. */
1012 #define IS_SPECULATION_BRANCHY_CHECK_P(INSN) \
1013 (RECOVERY_BLOCK (INSN) != NULL \
1014 && RECOVERY_BLOCK (INSN) != EXIT_BLOCK_PTR_FOR_FN (cfun))
1017 /* Dep status (aka ds_t) of the link encapsulates all information for a given
1018 dependency, including everything that is needed for speculative scheduling.
1020 The lay-out of a ds_t is as follows:
1022 1. Integers corresponding to the probability of the dependence to *not*
1023 exist. This is the probability that overcoming this dependence will
1024 not be followed by execution of the recovery code. Note that however
1025 high this probability is, the recovery code should still always be
1026 generated to preserve semantics of the program.
1028 The probability values can be set or retrieved using the functions
1029 the set_dep_weak() and get_dep_weak() in sched-deps.cc. The values
1030 are always in the range [0, MAX_DEP_WEAK].
1032 BEGIN_DATA : BITS_PER_DEP_WEAK
1033 BE_IN_DATA : BITS_PER_DEP_WEAK
1034 BEGIN_CONTROL : BITS_PER_DEP_WEAK
1035 BE_IN_CONTROL : BITS_PER_DEP_WEAK
1037 The basic type of DS_T is a host int. For a 32-bits int, the values
1038 will each take 6 bits.
1040 2. The type of dependence. This supercedes the old-style REG_NOTE_KIND
1041 values. TODO: Use this field instead of DEP_TYPE, or make DEP_TYPE
1042 extract the dependence type from here.
1044 dep_type : 4 => DEP_{TRUE|OUTPUT|ANTI|CONTROL}
1046 3. Various flags:
1048 HARD_DEP : 1 => Set if an instruction has a non-speculative
1049 dependence. This is an instruction property
1050 so this bit can only appear in the TODO_SPEC
1051 field of an instruction.
1052 DEP_POSTPONED : 1 => Like HARD_DEP, but the hard dependence may
1053 still be broken by adjusting the instruction.
1054 DEP_CANCELLED : 1 => Set if a dependency has been broken using
1055 some form of speculation.
1056 RESERVED : 1 => Reserved for use in the delay slot scheduler.
1058 See also: check_dep_status () in sched-deps.cc . */
1060 /* The number of bits per weakness probability. There are 4 weakness types
1061 and we need 8 bits for other data in a DS_T. */
1062 #define BITS_PER_DEP_WEAK ((BITS_PER_DEP_STATUS - 8) / 4)
1064 /* Mask of speculative weakness in dep_status. */
1065 #define DEP_WEAK_MASK ((1 << BITS_PER_DEP_WEAK) - 1)
1067 /* This constant means that dependence is fake with 99.999...% probability.
1068 This is the maximum value, that can appear in dep_status.
1069 Note, that we don't want MAX_DEP_WEAK to be the same as DEP_WEAK_MASK for
1070 debugging reasons. Though, it can be set to DEP_WEAK_MASK, and, when
1071 done so, we'll get fast (mul for)/(div by) NO_DEP_WEAK. */
1072 #define MAX_DEP_WEAK (DEP_WEAK_MASK - 1)
1074 /* This constant means that dependence is 99.999...% real and it is a really
1075 bad idea to overcome it (though this can be done, preserving program
1076 semantics). */
1077 #define MIN_DEP_WEAK 1
1079 /* This constant represents 100% probability.
1080 E.g. it is used to represent weakness of dependence, that doesn't exist.
1081 This value never appears in a ds_t, it is only used for computing the
1082 weakness of a dependence. */
1083 #define NO_DEP_WEAK (MAX_DEP_WEAK + MIN_DEP_WEAK)
1085 /* Default weakness of speculative dependence. Used when we can't say
1086 neither bad nor good about the dependence. */
1087 #define UNCERTAIN_DEP_WEAK (MAX_DEP_WEAK - MAX_DEP_WEAK / 4)
1089 /* Offset for speculative weaknesses in dep_status. */
1090 enum SPEC_TYPES_OFFSETS {
1091 BEGIN_DATA_BITS_OFFSET = 0,
1092 BE_IN_DATA_BITS_OFFSET = BEGIN_DATA_BITS_OFFSET + BITS_PER_DEP_WEAK,
1093 BEGIN_CONTROL_BITS_OFFSET = BE_IN_DATA_BITS_OFFSET + BITS_PER_DEP_WEAK,
1094 BE_IN_CONTROL_BITS_OFFSET = BEGIN_CONTROL_BITS_OFFSET + BITS_PER_DEP_WEAK
1097 /* The following defines provide numerous constants used to distinguish
1098 between different types of speculative dependencies. They are also
1099 used as masks to clear/preserve the bits corresponding to the type
1100 of dependency weakness. */
1102 /* Dependence can be overcome with generation of new data speculative
1103 instruction. */
1104 #define BEGIN_DATA (((ds_t) DEP_WEAK_MASK) << BEGIN_DATA_BITS_OFFSET)
1106 /* This dependence is to the instruction in the recovery block, that was
1107 formed to recover after data-speculation failure.
1108 Thus, this dependence can overcome with generating of the copy of
1109 this instruction in the recovery block. */
1110 #define BE_IN_DATA (((ds_t) DEP_WEAK_MASK) << BE_IN_DATA_BITS_OFFSET)
1112 /* Dependence can be overcome with generation of new control speculative
1113 instruction. */
1114 #define BEGIN_CONTROL (((ds_t) DEP_WEAK_MASK) << BEGIN_CONTROL_BITS_OFFSET)
1116 /* This dependence is to the instruction in the recovery block, that was
1117 formed to recover after control-speculation failure.
1118 Thus, this dependence can be overcome with generating of the copy of
1119 this instruction in the recovery block. */
1120 #define BE_IN_CONTROL (((ds_t) DEP_WEAK_MASK) << BE_IN_CONTROL_BITS_OFFSET)
1122 /* A few convenient combinations. */
1123 #define BEGIN_SPEC (BEGIN_DATA | BEGIN_CONTROL)
1124 #define DATA_SPEC (BEGIN_DATA | BE_IN_DATA)
1125 #define CONTROL_SPEC (BEGIN_CONTROL | BE_IN_CONTROL)
1126 #define SPECULATIVE (DATA_SPEC | CONTROL_SPEC)
1127 #define BE_IN_SPEC (BE_IN_DATA | BE_IN_CONTROL)
1129 /* Constants, that are helpful in iterating through dep_status. */
1130 #define FIRST_SPEC_TYPE BEGIN_DATA
1131 #define LAST_SPEC_TYPE BE_IN_CONTROL
1132 #define SPEC_TYPE_SHIFT BITS_PER_DEP_WEAK
1134 /* Dependence on instruction can be of multiple types
1135 (e.g. true and output). This fields enhance REG_NOTE_KIND information
1136 of the dependence. */
1137 #define DEP_TRUE (((ds_t) 1) << (BE_IN_CONTROL_BITS_OFFSET + BITS_PER_DEP_WEAK))
1138 #define DEP_OUTPUT (DEP_TRUE << 1)
1139 #define DEP_ANTI (DEP_OUTPUT << 1)
1140 #define DEP_CONTROL (DEP_ANTI << 1)
1142 #define DEP_TYPES (DEP_TRUE | DEP_OUTPUT | DEP_ANTI | DEP_CONTROL)
1144 /* Instruction has non-speculative dependence. This bit represents the
1145 property of an instruction - not the one of a dependence.
1146 Therefore, it can appear only in the TODO_SPEC field of an instruction. */
1147 #define HARD_DEP (DEP_CONTROL << 1)
1149 /* Like HARD_DEP, but dependencies can perhaps be broken by modifying
1150 the instructions. This is used for example to change:
1152 rn++ => rm=[rn + 4]
1153 rm=[rn] rn++
1155 For instructions that have this bit set, one of the dependencies of
1156 the instructions will have a non-NULL REPLACE field in its DEP_T.
1157 Just like HARD_DEP, this bit is only ever set in TODO_SPEC. */
1158 #define DEP_POSTPONED (HARD_DEP << 1)
1160 /* Set if a dependency is cancelled via speculation. */
1161 #define DEP_CANCELLED (DEP_POSTPONED << 1)
1164 /* This represents the results of calling sched-deps.cc functions,
1165 which modify dependencies. */
1166 enum DEPS_ADJUST_RESULT {
1167 /* No dependence needed (e.g. producer == consumer). */
1168 DEP_NODEP,
1169 /* Dependence is already present and wasn't modified. */
1170 DEP_PRESENT,
1171 /* Existing dependence was modified to include additional information. */
1172 DEP_CHANGED,
1173 /* New dependence has been created. */
1174 DEP_CREATED
1177 /* Represents the bits that can be set in the flags field of the
1178 sched_info structure. */
1179 enum SCHED_FLAGS {
1180 /* If set, generate links between instruction as DEPS_LIST.
1181 Otherwise, generate usual INSN_LIST links. */
1182 USE_DEPS_LIST = 1,
1183 /* Perform data or control (or both) speculation.
1184 Results in generation of data and control speculative dependencies.
1185 Requires USE_DEPS_LIST set. */
1186 DO_SPECULATION = USE_DEPS_LIST << 1,
1187 DO_BACKTRACKING = DO_SPECULATION << 1,
1188 DO_PREDICATION = DO_BACKTRACKING << 1,
1189 DONT_BREAK_DEPENDENCIES = DO_PREDICATION << 1,
1190 SCHED_RGN = DONT_BREAK_DEPENDENCIES << 1,
1191 SCHED_EBB = SCHED_RGN << 1,
1192 /* Scheduler can possibly create new basic blocks. Used for assertions. */
1193 NEW_BBS = SCHED_EBB << 1,
1194 SEL_SCHED = NEW_BBS << 1
1197 enum SPEC_SCHED_FLAGS {
1198 COUNT_SPEC_IN_CRITICAL_PATH = 1,
1199 SEL_SCHED_SPEC_DONT_CHECK_CONTROL = COUNT_SPEC_IN_CRITICAL_PATH << 1
1202 #define NOTE_NOT_BB_P(NOTE) (NOTE_P (NOTE) && (NOTE_KIND (NOTE) \
1203 != NOTE_INSN_BASIC_BLOCK))
1205 extern FILE *sched_dump;
1206 extern int sched_verbose;
1208 extern spec_info_t spec_info;
1209 extern bool haifa_recovery_bb_ever_added_p;
1211 /* Exception Free Loads:
1213 We define five classes of speculative loads: IFREE, IRISKY,
1214 PFREE, PRISKY, and MFREE.
1216 IFREE loads are loads that are proved to be exception-free, just
1217 by examining the load insn. Examples for such loads are loads
1218 from TOC and loads of global data.
1220 IRISKY loads are loads that are proved to be exception-risky,
1221 just by examining the load insn. Examples for such loads are
1222 volatile loads and loads from shared memory.
1224 PFREE loads are loads for which we can prove, by examining other
1225 insns, that they are exception-free. Currently, this class consists
1226 of loads for which we are able to find a "similar load", either in
1227 the target block, or, if only one split-block exists, in that split
1228 block. Load2 is similar to load1 if both have same single base
1229 register. We identify only part of the similar loads, by finding
1230 an insn upon which both load1 and load2 have a DEF-USE dependence.
1232 PRISKY loads are loads for which we can prove, by examining other
1233 insns, that they are exception-risky. Currently we have two proofs for
1234 such loads. The first proof detects loads that are probably guarded by a
1235 test on the memory address. This proof is based on the
1236 backward and forward data dependence information for the region.
1237 Let load-insn be the examined load.
1238 Load-insn is PRISKY iff ALL the following hold:
1240 - insn1 is not in the same block as load-insn
1241 - there is a DEF-USE dependence chain (insn1, ..., load-insn)
1242 - test-insn is either a compare or a branch, not in the same block
1243 as load-insn
1244 - load-insn is reachable from test-insn
1245 - there is a DEF-USE dependence chain (insn1, ..., test-insn)
1247 This proof might fail when the compare and the load are fed
1248 by an insn not in the region. To solve this, we will add to this
1249 group all loads that have no input DEF-USE dependence.
1251 The second proof detects loads that are directly or indirectly
1252 fed by a speculative load. This proof is affected by the
1253 scheduling process. We will use the flag fed_by_spec_load.
1254 Initially, all insns have this flag reset. After a speculative
1255 motion of an insn, if insn is either a load, or marked as
1256 fed_by_spec_load, we will also mark as fed_by_spec_load every
1257 insn1 for which a DEF-USE dependence (insn, insn1) exists. A
1258 load which is fed_by_spec_load is also PRISKY.
1260 MFREE (maybe-free) loads are all the remaining loads. They may be
1261 exception-free, but we cannot prove it.
1263 Now, all loads in IFREE and PFREE classes are considered
1264 exception-free, while all loads in IRISKY and PRISKY classes are
1265 considered exception-risky. As for loads in the MFREE class,
1266 these are considered either exception-free or exception-risky,
1267 depending on whether we are pessimistic or optimistic. We have
1268 to take the pessimistic approach to assure the safety of
1269 speculative scheduling, but we can take the optimistic approach
1270 by invoking the -fsched_spec_load_dangerous option. */
1272 enum INSN_TRAP_CLASS
1274 TRAP_FREE = 0, IFREE = 1, PFREE_CANDIDATE = 2,
1275 PRISKY_CANDIDATE = 3, IRISKY = 4, TRAP_RISKY = 5
1278 #define WORST_CLASS(class1, class2) \
1279 ((class1 > class2) ? class1 : class2)
1281 #ifndef __GNUC__
1282 #define __inline
1283 #endif
1285 #ifndef HAIFA_INLINE
1286 #define HAIFA_INLINE __inline
1287 #endif
1289 struct sched_deps_info_def
1291 /* Called when computing dependencies for a JUMP_INSN. This function
1292 should store the set of registers that must be considered as set by
1293 the jump in the regset. */
1294 void (*compute_jump_reg_dependencies) (rtx, regset);
1296 /* Start analyzing insn. */
1297 void (*start_insn) (rtx_insn *);
1299 /* Finish analyzing insn. */
1300 void (*finish_insn) (void);
1302 /* Start analyzing insn LHS (Left Hand Side). */
1303 void (*start_lhs) (rtx);
1305 /* Finish analyzing insn LHS. */
1306 void (*finish_lhs) (void);
1308 /* Start analyzing insn RHS (Right Hand Side). */
1309 void (*start_rhs) (rtx);
1311 /* Finish analyzing insn RHS. */
1312 void (*finish_rhs) (void);
1314 /* Note set of the register. */
1315 void (*note_reg_set) (int);
1317 /* Note clobber of the register. */
1318 void (*note_reg_clobber) (int);
1320 /* Note use of the register. */
1321 void (*note_reg_use) (int);
1323 /* Note memory dependence of type DS between MEM1 and MEM2 (which is
1324 in the INSN2). */
1325 void (*note_mem_dep) (rtx mem1, rtx mem2, rtx_insn *insn2, ds_t ds);
1327 /* Note a dependence of type DS from the INSN. */
1328 void (*note_dep) (rtx_insn *, ds_t ds);
1330 /* Nonzero if we should use cselib for better alias analysis. This
1331 must be 0 if the dependency information is used after sched_analyze
1332 has completed, e.g. if we're using it to initialize state for successor
1333 blocks in region scheduling. */
1334 unsigned int use_cselib : 1;
1336 /* If set, generate links between instruction as DEPS_LIST.
1337 Otherwise, generate usual INSN_LIST links. */
1338 unsigned int use_deps_list : 1;
1340 /* Generate data and control speculative dependencies.
1341 Requires USE_DEPS_LIST set. */
1342 unsigned int generate_spec_deps : 1;
1345 extern struct sched_deps_info_def *sched_deps_info;
1348 /* Functions in sched-deps.cc. */
1349 extern rtx sched_get_reverse_condition_uncached (const rtx_insn *);
1350 extern bool sched_insns_conditions_mutex_p (const rtx_insn *,
1351 const rtx_insn *);
1352 extern bool sched_insn_is_legitimate_for_speculation_p (const rtx_insn *, ds_t);
1353 extern void add_dependence (rtx_insn *, rtx_insn *, enum reg_note);
1354 extern void sched_analyze (class deps_desc *, rtx_insn *, rtx_insn *);
1355 extern void init_deps (class deps_desc *, bool);
1356 extern void init_deps_reg_last (class deps_desc *);
1357 extern void free_deps (class deps_desc *);
1358 extern void init_deps_global (void);
1359 extern void finish_deps_global (void);
1360 extern void deps_analyze_insn (class deps_desc *, rtx_insn *);
1361 extern void remove_from_deps (class deps_desc *, rtx_insn *);
1362 extern void init_insn_reg_pressure_info (rtx_insn *);
1363 extern void get_implicit_reg_pending_clobbers (HARD_REG_SET *, rtx_insn *);
1365 extern dw_t get_dep_weak (ds_t, ds_t);
1366 extern ds_t set_dep_weak (ds_t, ds_t, dw_t);
1367 extern dw_t estimate_dep_weak (rtx, rtx);
1368 extern ds_t ds_merge (ds_t, ds_t);
1369 extern ds_t ds_full_merge (ds_t, ds_t, rtx, rtx);
1370 extern ds_t ds_max_merge (ds_t, ds_t);
1371 extern dw_t ds_weak (ds_t);
1372 extern ds_t ds_get_speculation_types (ds_t);
1373 extern ds_t ds_get_max_dep_weak (ds_t);
1375 extern void sched_deps_init (bool);
1376 extern void sched_deps_finish (void);
1378 extern void haifa_note_reg_set (int);
1379 extern void haifa_note_reg_clobber (int);
1380 extern void haifa_note_reg_use (int);
1382 extern void maybe_extend_reg_info_p (void);
1384 extern void deps_start_bb (class deps_desc *, rtx_insn *);
1385 extern enum reg_note ds_to_dt (ds_t);
1387 extern bool deps_pools_are_empty_p (void);
1388 extern void sched_free_deps (rtx_insn *, rtx_insn *, bool);
1389 extern void extend_dependency_caches (int, bool);
1391 extern void debug_ds (ds_t);
1394 /* Functions in haifa-sched.cc. */
1395 extern void initialize_live_range_shrinkage (void);
1396 extern void finish_live_range_shrinkage (void);
1397 extern void sched_init_region_reg_pressure_info (void);
1398 extern void free_global_sched_pressure_data (void);
1399 extern int haifa_classify_insn (const_rtx);
1400 extern void get_ebb_head_tail (basic_block, basic_block,
1401 rtx_insn **, rtx_insn **);
1402 extern bool no_real_insns_p (const rtx_insn *, const rtx_insn *);
1404 extern int insn_sched_cost (rtx_insn *);
1405 extern int dep_cost_1 (dep_t, dw_t);
1406 extern int dep_cost (dep_t);
1407 extern int set_priorities (rtx_insn *, rtx_insn *);
1409 extern void sched_setup_bb_reg_pressure_info (basic_block, rtx_insn *);
1410 extern bool schedule_block (basic_block *, state_t);
1412 extern int cycle_issued_insns;
1413 extern int issue_rate;
1414 extern int dfa_lookahead;
1416 extern int autopref_multipass_dfa_lookahead_guard (rtx_insn *, int);
1418 extern rtx_insn *ready_element (struct ready_list *, int);
1419 extern rtx_insn **ready_lastpos (struct ready_list *);
1421 extern int try_ready (rtx_insn *);
1422 extern void sched_extend_ready_list (int);
1423 extern void sched_finish_ready_list (void);
1424 extern void sched_change_pattern (rtx, rtx);
1425 extern int sched_speculate_insn (rtx_insn *, ds_t, rtx *);
1426 extern void unlink_bb_notes (basic_block, basic_block);
1427 extern void add_block (basic_block, basic_block);
1428 extern rtx_note *bb_note (basic_block);
1429 extern void concat_note_lists (rtx_insn *, rtx_insn **);
1430 extern rtx_insn *sched_emit_insn (rtx);
1431 extern rtx_insn *get_ready_element (int);
1432 extern int number_in_ready (void);
1434 /* Types and functions in sched-ebb.cc. */
1436 extern basic_block schedule_ebb (rtx_insn *, rtx_insn *, bool);
1437 extern void schedule_ebbs_init (void);
1438 extern void schedule_ebbs_finish (void);
1440 /* Types and functions in sched-rgn.cc. */
1442 /* A region is the main entity for interblock scheduling: insns
1443 are allowed to move between blocks in the same region, along
1444 control flow graph edges, in the 'up' direction. */
1445 struct region
1447 /* Number of extended basic blocks in region. */
1448 int rgn_nr_blocks;
1449 /* cblocks in the region (actually index in rgn_bb_table). */
1450 int rgn_blocks;
1451 /* Dependencies for this region are already computed. Basically, indicates,
1452 that this is a recovery block. */
1453 unsigned int dont_calc_deps : 1;
1454 /* This region has at least one non-trivial ebb. */
1455 unsigned int has_real_ebb : 1;
1458 extern int nr_regions;
1459 extern region *rgn_table;
1460 extern int *rgn_bb_table;
1461 extern int *block_to_bb;
1462 extern int *containing_rgn;
1464 /* Often used short-hand in the scheduler. The rest of the compiler uses
1465 BLOCK_FOR_INSN(INSN) and an indirect reference to get the basic block
1466 number ("index"). For historical reasons, the scheduler does not. */
1467 #define BLOCK_NUM(INSN) (BLOCK_FOR_INSN (INSN)->index + 0)
1469 #define RGN_NR_BLOCKS(rgn) (rgn_table[rgn].rgn_nr_blocks)
1470 #define RGN_BLOCKS(rgn) (rgn_table[rgn].rgn_blocks)
1471 #define RGN_DONT_CALC_DEPS(rgn) (rgn_table[rgn].dont_calc_deps)
1472 #define RGN_HAS_REAL_EBB(rgn) (rgn_table[rgn].has_real_ebb)
1473 #define BLOCK_TO_BB(block) (block_to_bb[block])
1474 #define CONTAINING_RGN(block) (containing_rgn[block])
1476 /* The mapping from ebb to block. */
1477 extern int *ebb_head;
1478 #define BB_TO_BLOCK(ebb) (rgn_bb_table[ebb_head[ebb]])
1479 #define EBB_FIRST_BB(ebb) BASIC_BLOCK_FOR_FN (cfun, BB_TO_BLOCK (ebb))
1480 #define EBB_LAST_BB(ebb) \
1481 BASIC_BLOCK_FOR_FN (cfun, rgn_bb_table[ebb_head[ebb + 1] - 1])
1482 #define INSN_BB(INSN) (BLOCK_TO_BB (BLOCK_NUM (INSN)))
1484 extern int current_nr_blocks;
1485 extern int current_blocks;
1486 extern int target_bb;
1487 extern bool sched_no_dce;
1489 extern void set_modulo_params (int, int, int, int);
1490 extern void record_delay_slot_pair (rtx_insn *, rtx_insn *, int, int);
1491 extern rtx_insn *real_insn_for_shadow (rtx_insn *);
1492 extern void discard_delay_pairs_above (int);
1493 extern void free_delay_pairs (void);
1494 extern void add_delay_dependencies (rtx_insn *);
1495 extern bool sched_is_disabled_for_current_region_p (void);
1496 extern void sched_rgn_init (bool);
1497 extern void sched_rgn_finish (void);
1498 extern void rgn_setup_region (int);
1499 extern void sched_rgn_compute_dependencies (int);
1500 extern void sched_rgn_local_init (int);
1501 extern void sched_rgn_local_finish (void);
1502 extern void sched_rgn_local_free (void);
1503 extern void extend_regions (void);
1504 extern void rgn_make_new_region_out_of_new_block (basic_block);
1506 extern void compute_priorities (void);
1507 extern void increase_insn_priority (rtx_insn *, int);
1508 extern void debug_rgn_dependencies (int);
1509 extern void debug_dependencies (rtx_insn *, rtx_insn *);
1510 extern void dump_rgn_dependencies_dot (FILE *);
1511 extern void dump_rgn_dependencies_dot (const char *);
1513 extern void free_rgn_deps (void);
1514 extern bool contributes_to_priority (rtx_insn *, rtx_insn *);
1515 extern void extend_rgns (int *, int *, sbitmap, int *);
1516 extern void deps_join (class deps_desc *, class deps_desc *);
1518 extern void rgn_setup_common_sched_info (void);
1519 extern void rgn_setup_sched_infos (void);
1521 extern void debug_regions (void);
1522 extern void debug_region (int);
1523 extern void dump_region_dot (FILE *, int);
1524 extern void dump_region_dot_file (const char *, int);
1526 extern void haifa_sched_init (void);
1527 extern void haifa_sched_finish (void);
1529 extern void find_modifiable_mems (rtx_insn *, rtx_insn *);
1531 /* sched-deps.cc interface to walk, add, search, update, resolve, delete
1532 and debug instruction dependencies. */
1534 /* Constants defining dependences lists. */
1536 /* No list. */
1537 #define SD_LIST_NONE (0)
1539 /* hard_back_deps. */
1540 #define SD_LIST_HARD_BACK (1)
1542 /* spec_back_deps. */
1543 #define SD_LIST_SPEC_BACK (2)
1545 /* forw_deps. */
1546 #define SD_LIST_FORW (4)
1548 /* resolved_back_deps. */
1549 #define SD_LIST_RES_BACK (8)
1551 /* resolved_forw_deps. */
1552 #define SD_LIST_RES_FORW (16)
1554 #define SD_LIST_BACK (SD_LIST_HARD_BACK | SD_LIST_SPEC_BACK)
1556 /* A type to hold above flags. */
1557 typedef int sd_list_types_def;
1559 extern void sd_next_list (const_rtx, sd_list_types_def *, deps_list_t *, bool *);
1561 /* Iterator to walk through, resolve and delete dependencies. */
1562 struct _sd_iterator
1564 /* What lists to walk. Can be any combination of SD_LIST_* flags. */
1565 sd_list_types_def types;
1567 /* Instruction dependencies lists of which will be walked. */
1568 rtx insn;
1570 /* Pointer to the next field of the previous element. This is not
1571 simply a pointer to the next element to allow easy deletion from the
1572 list. When a dep is being removed from the list the iterator
1573 will automatically advance because the value in *linkp will start
1574 referring to the next element. */
1575 dep_link_t *linkp;
1577 /* True if the current list is a resolved one. */
1578 bool resolved_p;
1581 typedef struct _sd_iterator sd_iterator_def;
1583 /* ??? We can move some definitions that are used in below inline functions
1584 out of sched-int.h to sched-deps.cc provided that the below functions will
1585 become global externals.
1586 These definitions include:
1587 * struct _deps_list: opaque pointer is needed at global scope.
1588 * struct _dep_link: opaque pointer is needed at scope of sd_iterator_def.
1589 * struct _dep_node: opaque pointer is needed at scope of
1590 struct _deps_link. */
1592 /* Return initialized iterator. */
1593 inline sd_iterator_def
1594 sd_iterator_start (rtx insn, sd_list_types_def types)
1596 /* Some dep_link a pointer to which will return NULL. */
1597 static dep_link_t null_link = NULL;
1599 sd_iterator_def i;
1601 i.types = types;
1602 i.insn = insn;
1603 i.linkp = &null_link;
1605 /* Avoid 'uninitialized warning'. */
1606 i.resolved_p = false;
1608 return i;
1611 /* Return the current element. */
1612 inline bool
1613 sd_iterator_cond (sd_iterator_def *it_ptr, dep_t *dep_ptr)
1615 while (true)
1617 dep_link_t link = *it_ptr->linkp;
1619 if (link != NULL)
1621 *dep_ptr = DEP_LINK_DEP (link);
1622 return true;
1624 else
1626 sd_list_types_def types = it_ptr->types;
1628 if (types != SD_LIST_NONE)
1629 /* Switch to next list. */
1631 deps_list_t list;
1633 sd_next_list (it_ptr->insn,
1634 &it_ptr->types, &list, &it_ptr->resolved_p);
1636 if (list)
1638 it_ptr->linkp = &DEPS_LIST_FIRST (list);
1639 continue;
1643 *dep_ptr = NULL;
1644 return false;
1649 /* Advance iterator. */
1650 inline void
1651 sd_iterator_next (sd_iterator_def *it_ptr)
1653 it_ptr->linkp = &DEP_LINK_NEXT (*it_ptr->linkp);
1656 /* A cycle wrapper. */
1657 #define FOR_EACH_DEP(INSN, LIST_TYPES, ITER, DEP) \
1658 for ((ITER) = sd_iterator_start ((INSN), (LIST_TYPES)); \
1659 sd_iterator_cond (&(ITER), &(DEP)); \
1660 sd_iterator_next (&(ITER)))
1662 #define IS_DISPATCH_ON 1
1663 #define IS_CMP 2
1664 #define DISPATCH_VIOLATION 3
1665 #define FITS_DISPATCH_WINDOW 4
1666 #define DISPATCH_INIT 5
1667 #define ADD_TO_DISPATCH_WINDOW 6
1669 extern int sd_lists_size (const_rtx, sd_list_types_def);
1670 extern bool sd_lists_empty_p (const_rtx, sd_list_types_def);
1671 extern void sd_init_insn (rtx_insn *);
1672 extern void sd_finish_insn (rtx_insn *);
1673 extern dep_t sd_find_dep_between (rtx, rtx, bool);
1674 extern void sd_add_dep (dep_t, bool);
1675 extern enum DEPS_ADJUST_RESULT sd_add_or_update_dep (dep_t, bool);
1676 extern void sd_resolve_dep (sd_iterator_def);
1677 extern void sd_unresolve_dep (sd_iterator_def);
1678 extern void sd_copy_back_deps (rtx_insn *, rtx_insn *, bool);
1679 extern void sd_delete_dep (sd_iterator_def);
1680 extern void sd_debug_lists (rtx, sd_list_types_def);
1682 extern int dep_list_size (rtx_insn *, sd_list_types_def);
1684 /* Macros and declarations for scheduling fusion. */
1685 #define FUSION_MAX_PRIORITY (INT_MAX)
1686 extern bool sched_fusion;
1688 #endif /* INSN_SCHEDULING */
1690 #endif /* GCC_SCHED_INT_H */