1/* Instruction scheduling pass.  This file contains definitions used
2   internally in the scheduler.
3   Copyright (C) 2006-2020 Free Software Foundation, Inc.
4
5This file is part of GCC.
6
7GCC is free software; you can redistribute it and/or modify it under
8the terms of the GNU General Public License as published by the Free
9Software Foundation; either version 3, or (at your option) any later
10version.
11
12GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13WARRANTY; without even the implied warranty of MERCHANTABILITY or
14FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
15for more details.
16
17You should have received a copy of the GNU General Public License
18along with GCC; see the file COPYING3.  If not see
19<http://www.gnu.org/licenses/>.  */
20
21#ifndef GCC_SEL_SCHED_IR_H
22#define GCC_SEL_SCHED_IR_H
23
24/* For state_t.  */
25/* For reg_note.  */
26
27/* tc_t is a short for target context.  This is a state of the target
28   backend.  */
29typedef void *tc_t;
30
31/* List data types used for av sets, fences, paths, and boundaries.  */
32
33/* Forward declarations for types that are part of some list nodes.  */
34struct _list_node;
35
36/* List backend.  */
37typedef struct _list_node *_list_t;
38#define _LIST_NEXT(L) ((L)->next)
39
40/* Instruction data that is part of vinsn type.  */
41struct idata_def;
42typedef struct idata_def *idata_t;
43
44/* A virtual instruction, i.e. an instruction as seen by the scheduler.  */
45struct vinsn_def;
46typedef struct vinsn_def *vinsn_t;
47
48/* RTX list.
49   This type is the backend for ilist.  */
50typedef _list_t _xlist_t;
51#define _XLIST_X(L) ((L)->u.x)
52#define _XLIST_NEXT(L) (_LIST_NEXT (L))
53
54/* Instruction.  */
55typedef rtx_insn *insn_t;
56
57/* List of insns.  */
58typedef _list_t ilist_t;
59#define ILIST_INSN(L) ((L)->u.insn)
60#define ILIST_NEXT(L) (_LIST_NEXT (L))
61
62/* This lists possible transformations that done locally, i.e. in
63   moveup_expr.  */
64enum local_trans_type
65  {
66    TRANS_SUBSTITUTION,
67    TRANS_SPECULATION
68  };
69
70/* This struct is used to record the history of expression's
71   transformations.  */
72struct expr_history_def_1
73{
74  /* UID of the insn.  */
75  unsigned uid;
76
77  /* How the expression looked like.  */
78  vinsn_t old_expr_vinsn;
79
80  /* How the expression looks after the transformation.  */
81  vinsn_t new_expr_vinsn;
82
83  /* And its speculative status.  */
84  ds_t spec_ds;
85
86  /* Type of the transformation.  */
87  enum local_trans_type type;
88};
89
90typedef struct expr_history_def_1 expr_history_def;
91
92
93/* Expression information.  */
94struct _expr
95{
96  /* Insn description.  */
97  vinsn_t vinsn;
98
99  /* SPEC is the degree of speculativeness.
100     FIXME: now spec is increased when an rhs is moved through a
101     conditional, thus showing only control speculativeness.  In the
102     future we'd like to count data spec separately to allow a better
103     control on scheduling.  */
104  int spec;
105
106  /* Degree of speculativeness measured as probability of executing
107     instruction's original basic block given relative to
108     the current scheduling point.  */
109  int usefulness;
110
111  /* A priority of this expression.  */
112  int priority;
113
114  /* A priority adjustment of this expression.  */
115  int priority_adj;
116
117  /* Number of times the insn was scheduled.  */
118  int sched_times;
119
120  /* A basic block index this was originated from.  Zero when there is
121     more than one originator.  */
122  int orig_bb_index;
123
124  /* Instruction should be of SPEC_DONE_DS type in order to be moved to this
125     point.  */
126  ds_t spec_done_ds;
127
128  /* SPEC_TO_CHECK_DS hold speculation types that should be checked
129     (used only during move_op ()).  */
130  ds_t spec_to_check_ds;
131
132  /* Cycle on which original insn was scheduled.  Zero when it has not yet
133     been scheduled or more than one originator.  */
134  int orig_sched_cycle;
135
136  /* This vector contains the history of insn's transformations.  */
137  vec<expr_history_def> history_of_changes;
138
139  /* True (1) when original target (register or memory) of this instruction
140     is available for scheduling, false otherwise.  -1 means we're not sure;
141     please run find_used_regs to clarify.  */
142  signed char target_available;
143
144  /* True when this expression needs a speculation check to be scheduled.
145     This is used during find_used_regs.  */
146  BOOL_BITFIELD needs_spec_check_p : 1;
147
148  /* True when the expression was substituted.  Used for statistical
149     purposes.  */
150  BOOL_BITFIELD was_substituted : 1;
151
152  /* True when the expression was renamed.  */
153  BOOL_BITFIELD was_renamed : 1;
154
155  /* True when expression can't be moved.  */
156  BOOL_BITFIELD cant_move : 1;
157};
158
159typedef struct _expr expr_def;
160typedef expr_def *expr_t;
161
162#define EXPR_VINSN(EXPR) ((EXPR)->vinsn)
163#define EXPR_INSN_RTX(EXPR) (VINSN_INSN_RTX (EXPR_VINSN (EXPR)))
164#define EXPR_PATTERN(EXPR) (VINSN_PATTERN (EXPR_VINSN (EXPR)))
165#define EXPR_LHS(EXPR) (VINSN_LHS (EXPR_VINSN (EXPR)))
166#define EXPR_RHS(EXPR) (VINSN_RHS (EXPR_VINSN (EXPR)))
167#define EXPR_TYPE(EXPR) (VINSN_TYPE (EXPR_VINSN (EXPR)))
168#define EXPR_SEPARABLE_P(EXPR) (VINSN_SEPARABLE_P (EXPR_VINSN (EXPR)))
169
170#define EXPR_SPEC(EXPR) ((EXPR)->spec)
171#define EXPR_USEFULNESS(EXPR) ((EXPR)->usefulness)
172#define EXPR_PRIORITY(EXPR) ((EXPR)->priority)
173#define EXPR_PRIORITY_ADJ(EXPR) ((EXPR)->priority_adj)
174#define EXPR_SCHED_TIMES(EXPR) ((EXPR)->sched_times)
175#define EXPR_ORIG_BB_INDEX(EXPR) ((EXPR)->orig_bb_index)
176#define EXPR_ORIG_SCHED_CYCLE(EXPR) ((EXPR)->orig_sched_cycle)
177#define EXPR_SPEC_DONE_DS(EXPR) ((EXPR)->spec_done_ds)
178#define EXPR_SPEC_TO_CHECK_DS(EXPR) ((EXPR)->spec_to_check_ds)
179#define EXPR_HISTORY_OF_CHANGES(EXPR) ((EXPR)->history_of_changes)
180#define EXPR_TARGET_AVAILABLE(EXPR) ((EXPR)->target_available)
181#define EXPR_NEEDS_SPEC_CHECK_P(EXPR) ((EXPR)->needs_spec_check_p)
182#define EXPR_WAS_SUBSTITUTED(EXPR) ((EXPR)->was_substituted)
183#define EXPR_WAS_RENAMED(EXPR) ((EXPR)->was_renamed)
184#define EXPR_CANT_MOVE(EXPR) ((EXPR)->cant_move)
185
186/* Insn definition for list of original insns in find_used_regs.  */
187struct _def
188{
189  insn_t orig_insn;
190
191  /* FIXME: Get rid of CROSSED_CALL_ABIS in each def, since if we're moving up
192     rhs from two different places, but only one of the code motion paths
193     crosses a call, we can't use any of the call_used_regs, no matter which
194     path or whether all paths crosses a call.  Thus we should move
195     CROSSED_CALL_ABIS to static params.  */
196  unsigned int crossed_call_abis;
197};
198typedef struct _def *def_t;
199
200
201/* Availability sets are sets of expressions we're scheduling.  */
202typedef _list_t av_set_t;
203#define _AV_SET_EXPR(L) (&(L)->u.expr)
204#define _AV_SET_NEXT(L) (_LIST_NEXT (L))
205
206
207/* Boundary of the current fence group.  */
208struct _bnd
209{
210  /* The actual boundary instruction.  */
211  insn_t to;
212
213  /* Its path to the fence.  */
214  ilist_t ptr;
215
216  /* Availability set at the boundary.  */
217  av_set_t av;
218
219  /* This set moved to the fence.  */
220  av_set_t av1;
221
222  /* Deps context at this boundary.  As long as we have one boundary per fence,
223     this is just a pointer to the same deps context as in the corresponding
224     fence.  */
225  deps_t dc;
226};
227typedef struct _bnd *bnd_t;
228#define BND_TO(B) ((B)->to)
229
230/* PTR stands not for pointer as you might think, but as a Path To Root of the
231   current instruction group from boundary B.  */
232#define BND_PTR(B) ((B)->ptr)
233#define BND_AV(B) ((B)->av)
234#define BND_AV1(B) ((B)->av1)
235#define BND_DC(B) ((B)->dc)
236
237/* List of boundaries.  */
238typedef _list_t blist_t;
239#define BLIST_BND(L) (&(L)->u.bnd)
240#define BLIST_NEXT(L) (_LIST_NEXT (L))
241
242
243/* Fence information.  A fence represents current scheduling point and also
244   blocks code motion through it when pipelining.  */
245struct _fence
246{
247  /* Insn before which we gather an instruction group.*/
248  insn_t insn;
249
250  /* Modeled state of the processor pipeline.  */
251  state_t state;
252
253  /* Current cycle that is being scheduled on this fence.  */
254  int cycle;
255
256  /* Number of insns that were scheduled on the current cycle.
257     This information has to be local to a fence.  */
258  int cycle_issued_insns;
259
260  /* At the end of fill_insns () this field holds the list of the instructions
261     that are inner boundaries of the scheduled parallel group.  */
262  ilist_t bnds;
263
264  /* Deps context at this fence.  It is used to model dependencies at the
265     fence so that insn ticks can be properly evaluated.  */
266  deps_t dc;
267
268  /* Target context at this fence.  Used to save and load any local target
269     scheduling information when changing fences.  */
270  tc_t tc;
271
272  /* A vector of insns that are scheduled but not yet completed.  */
273  vec<rtx_insn *, va_gc> *executing_insns;
274
275  /* A vector indexed by UIDs that caches the earliest cycle on which
276     an insn can be scheduled on this fence.  */
277  int *ready_ticks;
278
279  /* Its size.  */
280  int ready_ticks_size;
281
282  /* Insn, which has been scheduled last on this fence.  */
283  rtx_insn *last_scheduled_insn;
284
285  /* The last value of can_issue_more variable on this fence.  */
286  int issue_more;
287
288  /* If non-NULL force the next scheduled insn to be SCHED_NEXT.  */
289  rtx_insn *sched_next;
290
291  /* True if fill_insns processed this fence.  */
292  BOOL_BITFIELD processed_p : 1;
293
294  /* True if fill_insns actually scheduled something on this fence.  */
295  BOOL_BITFIELD scheduled_p : 1;
296
297  /* True when the next insn scheduled here would start a cycle.  */
298  BOOL_BITFIELD starts_cycle_p : 1;
299
300  /* True when the next insn scheduled here would be scheduled after a stall.  */
301  BOOL_BITFIELD after_stall_p : 1;
302};
303typedef struct _fence *fence_t;
304
305#define FENCE_INSN(F) ((F)->insn)
306#define FENCE_STATE(F) ((F)->state)
307#define FENCE_BNDS(F) ((F)->bnds)
308#define FENCE_PROCESSED_P(F) ((F)->processed_p)
309#define FENCE_SCHEDULED_P(F) ((F)->scheduled_p)
310#define FENCE_ISSUED_INSNS(F) ((F)->cycle_issued_insns)
311#define FENCE_CYCLE(F) ((F)->cycle)
312#define FENCE_STARTS_CYCLE_P(F) ((F)->starts_cycle_p)
313#define FENCE_AFTER_STALL_P(F) ((F)->after_stall_p)
314#define FENCE_DC(F) ((F)->dc)
315#define FENCE_TC(F) ((F)->tc)
316#define FENCE_LAST_SCHEDULED_INSN(F) ((F)->last_scheduled_insn)
317#define FENCE_ISSUE_MORE(F) ((F)->issue_more)
318#define FENCE_EXECUTING_INSNS(F) ((F)->executing_insns)
319#define FENCE_READY_TICKS(F) ((F)->ready_ticks)
320#define FENCE_READY_TICKS_SIZE(F) ((F)->ready_ticks_size)
321#define FENCE_SCHED_NEXT(F) ((F)->sched_next)
322
323/* List of fences.  */
324typedef _list_t flist_t;
325#define FLIST_FENCE(L) (&(L)->u.fence)
326#define FLIST_NEXT(L) (_LIST_NEXT (L))
327
328/* List of fences with pointer to the tail node.  */
329struct flist_tail_def
330{
331  flist_t head;
332  flist_t *tailp;
333};
334
335typedef struct flist_tail_def *flist_tail_t;
336#define FLIST_TAIL_HEAD(L) ((L)->head)
337#define FLIST_TAIL_TAILP(L) ((L)->tailp)
338
339/* List node information.  A list node can be any of the types above.  */
340struct _list_node
341{
342  _list_t next;
343
344  union
345  {
346    rtx x;
347    insn_t insn;
348    struct _bnd bnd;
349    expr_def expr;
350    struct _fence fence;
351    struct _def def;
352    void *data;
353  } u;
354};
355
356
357/* _list_t functions.
358   All of _*list_* functions are used through accessor macros, thus
359   we can't move them in sel-sched-ir.c.  */
360extern object_allocator<_list_node> sched_lists_pool;
361
362static inline _list_t
363_list_alloc (void)
364{
365  return sched_lists_pool.allocate ();
366}
367
368static inline void
369_list_add (_list_t *lp)
370{
371  _list_t l = _list_alloc ();
372
373  _LIST_NEXT (l) = *lp;
374  *lp = l;
375}
376
377static inline void
378_list_remove_nofree (_list_t *lp)
379{
380  _list_t n = *lp;
381
382  *lp = _LIST_NEXT (n);
383}
384
385static inline void
386_list_remove (_list_t *lp)
387{
388  _list_t n = *lp;
389
390  *lp = _LIST_NEXT (n);
391  sched_lists_pool.remove (n);
392}
393
394static inline void
395_list_clear (_list_t *l)
396{
397  while (*l)
398    _list_remove (l);
399}
400
401
402/* List iterator backend.  */
403struct _list_iterator
404{
405  /* The list we're iterating.  */
406  _list_t *lp;
407
408  /* True when this iterator supprts removing.  */
409  bool can_remove_p;
410
411  /* True when we've actually removed something.  */
412  bool removed_p;
413};
414
415static inline void
416_list_iter_start (_list_iterator *ip, _list_t *lp, bool can_remove_p)
417{
418  ip->lp = lp;
419  ip->can_remove_p = can_remove_p;
420  ip->removed_p = false;
421}
422
423static inline void
424_list_iter_next (_list_iterator *ip)
425{
426  if (!ip->removed_p)
427    ip->lp = &_LIST_NEXT (*ip->lp);
428  else
429    ip->removed_p = false;
430}
431
432static inline void
433_list_iter_remove (_list_iterator *ip)
434{
435  gcc_assert (!ip->removed_p && ip->can_remove_p);
436  _list_remove (ip->lp);
437  ip->removed_p = true;
438}
439
440static inline void
441_list_iter_remove_nofree (_list_iterator *ip)
442{
443  gcc_assert (!ip->removed_p && ip->can_remove_p);
444  _list_remove_nofree (ip->lp);
445  ip->removed_p = true;
446}
447
448/* General macros to traverse a list.  FOR_EACH_* interfaces are
449   implemented using these.  */
450#define _FOR_EACH(TYPE, ELEM, I, L)				\
451  for (_list_iter_start (&(I), &(L), false);			\
452       _list_iter_cond_##TYPE (*(I).lp, &(ELEM));		\
453       _list_iter_next (&(I)))
454
455#define _FOR_EACH_1(TYPE, ELEM, I, LP)                              \
456  for (_list_iter_start (&(I), (LP), true);                         \
457       _list_iter_cond_##TYPE (*(I).lp, &(ELEM));                   \
458       _list_iter_next (&(I)))
459
460
461/* _xlist_t functions.  */
462
463static inline void
464_xlist_add (_xlist_t *lp, rtx x)
465{
466  _list_add (lp);
467  _XLIST_X (*lp) = x;
468}
469
470#define _xlist_remove(LP) (_list_remove (LP))
471#define _xlist_clear(LP) (_list_clear (LP))
472
473static inline bool
474_xlist_is_in_p (_xlist_t l, rtx x)
475{
476  while (l)
477    {
478      if (_XLIST_X (l) == x)
479        return true;
480      l = _XLIST_NEXT (l);
481    }
482
483  return false;
484}
485
486/* Used through _FOR_EACH.  */
487static inline bool
488_list_iter_cond_x (_xlist_t l, rtx *xp)
489{
490  if (l)
491    {
492      *xp = _XLIST_X (l);
493      return true;
494    }
495
496  return false;
497}
498
499#define _xlist_iter_remove(IP) (_list_iter_remove (IP))
500
501typedef _list_iterator _xlist_iterator;
502#define _FOR_EACH_X(X, I, L) _FOR_EACH (x, (X), (I), (L))
503#define _FOR_EACH_X_1(X, I, LP) _FOR_EACH_1 (x, (X), (I), (LP))
504
505
506/* ilist_t functions.  */
507
508static inline void
509ilist_add (ilist_t *lp, insn_t insn)
510{
511  _list_add (lp);
512  ILIST_INSN (*lp) = insn;
513}
514#define ilist_remove(LP) (_list_remove (LP))
515#define ilist_clear(LP) (_list_clear (LP))
516
517static inline bool
518ilist_is_in_p (ilist_t l, insn_t insn)
519{
520  while (l)
521    {
522      if (ILIST_INSN (l) == insn)
523        return true;
524      l = ILIST_NEXT (l);
525    }
526
527  return false;
528}
529
530/* Used through _FOR_EACH.  */
531static inline bool
532_list_iter_cond_insn (ilist_t l, insn_t *ip)
533{
534  if (l)
535    {
536      *ip = ILIST_INSN (l);
537      return true;
538    }
539
540  return false;
541}
542
543#define ilist_iter_remove(IP) (_list_iter_remove (IP))
544
545typedef _list_iterator ilist_iterator;
546#define FOR_EACH_INSN(INSN, I, L) _FOR_EACH (insn, (INSN), (I), (L))
547#define FOR_EACH_INSN_1(INSN, I, LP) _FOR_EACH_1 (insn, (INSN), (I), (LP))
548
549
550/* Av set iterators.  */
551typedef _list_iterator av_set_iterator;
552#define FOR_EACH_EXPR(EXPR, I, AV) _FOR_EACH (expr, (EXPR), (I), (AV))
553#define FOR_EACH_EXPR_1(EXPR, I, AV) _FOR_EACH_1 (expr, (EXPR), (I), (AV))
554
555inline bool
556_list_iter_cond_expr (av_set_t av, expr_t *exprp)
557{
558  if (av)
559    {
560      *exprp = _AV_SET_EXPR (av);
561      return true;
562    }
563
564  return false;
565}
566
567
568/* Def list iterators.  */
569typedef _list_t def_list_t;
570typedef _list_iterator def_list_iterator;
571
572#define DEF_LIST_NEXT(L) (_LIST_NEXT (L))
573#define DEF_LIST_DEF(L) (&(L)->u.def)
574
575#define FOR_EACH_DEF(DEF, I, DEF_LIST) _FOR_EACH (def, (DEF), (I), (DEF_LIST))
576
577static inline bool
578_list_iter_cond_def (def_list_t def_list, def_t *def)
579{
580  if (def_list)
581    {
582      *def = DEF_LIST_DEF (def_list);
583      return true;
584    }
585
586  return false;
587}
588
589
590/* InstructionData.  Contains information about insn pattern.  */
591struct idata_def
592{
593  /* Type of the insn.
594     o CALL_INSN - Call insn
595     o JUMP_INSN - Jump insn
596     o INSN - INSN that cannot be cloned
597     o USE - INSN that can be cloned
598     o SET - INSN that can be cloned and separable into lhs and rhs
599     o PC - simplejump.  Insns that simply redirect control flow should not
600     have any dependencies.  Sched-deps.c, though, might consider them as
601     producers or consumers of certain registers.  To avoid that we handle
602     dependency for simple jumps ourselves.  */
603  int type;
604
605  /* If insn is a SET, this is its left hand side.  */
606  rtx lhs;
607
608  /* If insn is a SET, this is its right hand side.  */
609  rtx rhs;
610
611  /* Registers that are set/used by this insn.  This info is now gathered
612     via sched-deps.c.  The downside of this is that we also use live info
613     from flow that is accumulated in the basic blocks.  These two infos
614     can be slightly inconsistent, hence in the beginning we make a pass
615     through CFG and calculating the conservative solution for the info in
616     basic blocks.  When this scheduler will be switched to use dataflow,
617     this can be unified as df gives us both per basic block and per
618     instruction info.  Actually, we don't do that pass and just hope
619     for the best.  */
620  regset reg_sets;
621
622  regset reg_clobbers;
623
624  regset reg_uses;
625};
626
627#define IDATA_TYPE(ID) ((ID)->type)
628#define IDATA_LHS(ID) ((ID)->lhs)
629#define IDATA_RHS(ID) ((ID)->rhs)
630#define IDATA_REG_SETS(ID) ((ID)->reg_sets)
631#define IDATA_REG_USES(ID) ((ID)->reg_uses)
632#define IDATA_REG_CLOBBERS(ID) ((ID)->reg_clobbers)
633
634/* Type to represent all needed info to emit an insn.
635   This is a virtual equivalent of the insn.
636   Every insn in the stream has an associated vinsn.  This is used
637   to reduce memory consumption basing on the fact that many insns
638   don't change through the scheduler.
639
640   vinsn can be either normal or unique.
641   * Normal vinsn is the one, that can be cloned multiple times and typically
642   corresponds to normal instruction.
643
644   * Unique vinsn derivates from CALL, ASM, JUMP (for a while) and other
645   unusual stuff.  Such a vinsn is described by its INSN field, which is a
646   reference to the original instruction.  */
647struct vinsn_def
648{
649  /* Associated insn.  */
650  rtx_insn *insn_rtx;
651
652  /* Its description.  */
653  struct idata_def id;
654
655  /* Hash of vinsn.  It is computed either from pattern or from rhs using
656     hash_rtx.  It is not placed in ID for faster compares.  */
657  unsigned hash;
658
659  /* Hash of the insn_rtx pattern.  */
660  unsigned hash_rtx;
661
662  /* Smart pointer counter.  */
663  int count;
664
665  /* Cached cost of the vinsn.  To access it please use vinsn_cost ().  */
666  int cost;
667
668  /* Mark insns that may trap so we don't move them through jumps.  */
669  bool may_trap_p;
670};
671
672#define VINSN_INSN_RTX(VI) ((VI)->insn_rtx)
673#define VINSN_PATTERN(VI) (PATTERN (VINSN_INSN_RTX (VI)))
674
675#define VINSN_ID(VI) (&((VI)->id))
676#define VINSN_HASH(VI) ((VI)->hash)
677#define VINSN_HASH_RTX(VI) ((VI)->hash_rtx)
678#define VINSN_TYPE(VI) (IDATA_TYPE (VINSN_ID (VI)))
679#define VINSN_SEPARABLE_P(VI) (VINSN_TYPE (VI) == SET)
680#define VINSN_CLONABLE_P(VI) (VINSN_SEPARABLE_P (VI) || VINSN_TYPE (VI) == USE)
681#define VINSN_UNIQUE_P(VI) (!VINSN_CLONABLE_P (VI))
682#define VINSN_LHS(VI) (IDATA_LHS (VINSN_ID (VI)))
683#define VINSN_RHS(VI) (IDATA_RHS (VINSN_ID (VI)))
684#define VINSN_REG_SETS(VI) (IDATA_REG_SETS (VINSN_ID (VI)))
685#define VINSN_REG_USES(VI) (IDATA_REG_USES (VINSN_ID (VI)))
686#define VINSN_REG_CLOBBERS(VI) (IDATA_REG_CLOBBERS (VINSN_ID (VI)))
687#define VINSN_COUNT(VI) ((VI)->count)
688#define VINSN_MAY_TRAP_P(VI) ((VI)->may_trap_p)
689
690
691/* An entry of the hashtable describing transformations happened when
692   moving up through an insn.  */
693struct transformed_insns
694{
695  /* Previous vinsn.  Used to find the proper element.  */
696  vinsn_t vinsn_old;
697
698  /* A new vinsn.  */
699  vinsn_t vinsn_new;
700
701  /* Speculative status.  */
702  ds_t ds;
703
704  /* Type of transformation happened.  */
705  enum local_trans_type type;
706
707  /* Whether a conflict on the target register happened.  */
708  BOOL_BITFIELD was_target_conflict : 1;
709
710  /* Whether a check was needed.  */
711  BOOL_BITFIELD needs_check : 1;
712};
713
714/* Indexed by INSN_LUID, the collection of all data associated with
715   a single instruction that is in the stream.  */
716class _sel_insn_data
717{
718public:
719  /* The expression that contains vinsn for this insn and some
720     flow-sensitive data like priority.  */
721  expr_def expr;
722
723  /* If (WS_LEVEL == GLOBAL_LEVEL) then AV is empty.  */
724  int ws_level;
725
726  /* A number that helps in defining a traversing order for a region.  */
727  int seqno;
728
729  /* A liveness data computed above this insn.  */
730  regset live;
731
732  /* An INSN_UID bit is set when deps analysis result is already known.  */
733  bitmap analyzed_deps;
734
735  /* An INSN_UID bit is set when a hard dep was found, not set when
736     no dependence is found.  This is meaningful only when the analyzed_deps
737     bitmap has its bit set.  */
738  bitmap found_deps;
739
740  /* An INSN_UID bit is set when this is a bookkeeping insn generated from
741     a parent with this uid.  If a parent is a bookkeeping copy, all its
742     originators are transitively included in this set.  */
743  bitmap originators;
744
745  /* A hashtable caching the result of insn transformations through this one.  */
746  htab_t transformed_insns;
747
748  /* A context incapsulating this insn.  */
749  class deps_desc deps_context;
750
751  /* This field is initialized at the beginning of scheduling and is used
752     to handle sched group instructions.  If it is non-null, then it points
753     to the instruction, which should be forced to schedule next.  Such
754     instructions are unique.  */
755  insn_t sched_next;
756
757  /* Cycle at which insn was scheduled.  It is greater than zero if insn was
758     scheduled.  This is used for bundling.  */
759  int sched_cycle;
760
761  /* Cycle at which insn's data will be fully ready.  */
762  int ready_cycle;
763
764  /* Speculations that are being checked by this insn.  */
765  ds_t spec_checked_ds;
766
767  /* Whether the live set valid or not.  */
768  BOOL_BITFIELD live_valid_p : 1;
769  /* Insn is an ASM.  */
770  BOOL_BITFIELD asm_p : 1;
771
772  /* True when an insn is scheduled after we've determined that a stall is
773     required.
774     This is used when emulating the Haifa scheduler for bundling.  */
775  BOOL_BITFIELD after_stall_p : 1;
776};
777
778typedef class _sel_insn_data sel_insn_data_def;
779typedef sel_insn_data_def *sel_insn_data_t;
780
781extern vec<sel_insn_data_def> s_i_d;
782
783/* Accessor macros for s_i_d.  */
784#define SID(INSN) (&s_i_d[INSN_LUID (INSN)])
785#define SID_BY_UID(UID) (&s_i_d[LUID_BY_UID (UID)])
786
787extern sel_insn_data_def insn_sid (insn_t);
788
789#define INSN_ASM_P(INSN) (SID (INSN)->asm_p)
790#define INSN_SCHED_NEXT(INSN) (SID (INSN)->sched_next)
791#define INSN_ANALYZED_DEPS(INSN) (SID (INSN)->analyzed_deps)
792#define INSN_FOUND_DEPS(INSN) (SID (INSN)->found_deps)
793#define INSN_DEPS_CONTEXT(INSN) (SID (INSN)->deps_context)
794#define INSN_ORIGINATORS(INSN) (SID (INSN)->originators)
795#define INSN_ORIGINATORS_BY_UID(UID) (SID_BY_UID (UID)->originators)
796#define INSN_TRANSFORMED_INSNS(INSN) (SID (INSN)->transformed_insns)
797
798#define INSN_EXPR(INSN) (&SID (INSN)->expr)
799#define INSN_LIVE(INSN) (SID (INSN)->live)
800#define INSN_LIVE_VALID_P(INSN) (SID (INSN)->live_valid_p)
801#define INSN_VINSN(INSN) (EXPR_VINSN (INSN_EXPR (INSN)))
802#define INSN_TYPE(INSN) (VINSN_TYPE (INSN_VINSN (INSN)))
803#define INSN_SIMPLEJUMP_P(INSN) (INSN_TYPE (INSN) == PC)
804#define INSN_LHS(INSN) (VINSN_LHS (INSN_VINSN (INSN)))
805#define INSN_RHS(INSN) (VINSN_RHS (INSN_VINSN (INSN)))
806#define INSN_REG_SETS(INSN) (VINSN_REG_SETS (INSN_VINSN (INSN)))
807#define INSN_REG_CLOBBERS(INSN) (VINSN_REG_CLOBBERS (INSN_VINSN (INSN)))
808#define INSN_REG_USES(INSN) (VINSN_REG_USES (INSN_VINSN (INSN)))
809#define INSN_SCHED_TIMES(INSN) (EXPR_SCHED_TIMES (INSN_EXPR (INSN)))
810#define INSN_SEQNO(INSN) (SID (INSN)->seqno)
811#define INSN_AFTER_STALL_P(INSN) (SID (INSN)->after_stall_p)
812#define INSN_SCHED_CYCLE(INSN) (SID (INSN)->sched_cycle)
813#define INSN_READY_CYCLE(INSN) (SID (INSN)->ready_cycle)
814#define INSN_SPEC_CHECKED_DS(INSN) (SID (INSN)->spec_checked_ds)
815
816/* A global level shows whether an insn is valid or not.  */
817extern int global_level;
818
819#define INSN_WS_LEVEL(INSN) (SID (INSN)->ws_level)
820
821extern av_set_t get_av_set (insn_t);
822extern int get_av_level (insn_t);
823
824#define AV_SET(INSN) (get_av_set (INSN))
825#define AV_LEVEL(INSN) (get_av_level (INSN))
826#define AV_SET_VALID_P(INSN) (AV_LEVEL (INSN) == global_level)
827
828/* A list of fences currently in the works.  */
829extern flist_t fences;
830
831/* A NOP pattern used as a placeholder for real insns.  */
832extern rtx nop_pattern;
833
834/* An insn that 'contained' in EXIT block.  */
835extern rtx_insn *exit_insn;
836
837/* Provide a separate luid for the insn.  */
838#define INSN_INIT_TODO_LUID (1)
839
840/* Initialize s_s_i_d.  */
841#define INSN_INIT_TODO_SSID (2)
842
843/* Initialize data for simplejump.  */
844#define INSN_INIT_TODO_SIMPLEJUMP (4)
845
846/* Return true if INSN is a local NOP.  The nop is local in the sense that
847   it was emitted by the scheduler as a temporary insn and will soon be
848   deleted.  These nops are identified by their pattern.  */
849#define INSN_NOP_P(INSN) (PATTERN (INSN) == nop_pattern)
850
851/* Return true if INSN is linked into instruction stream.
852   NB: It is impossible for INSN to have one field null and the other not
853   null: gcc_assert ((PREV_INSN (INSN) == NULL_RTX)
854   == (NEXT_INSN (INSN) == NULL_RTX)) is valid.  */
855#define INSN_IN_STREAM_P(INSN) (PREV_INSN (INSN) && NEXT_INSN (INSN))
856
857/* Return true if INSN is in current fence.  */
858#define IN_CURRENT_FENCE_P(INSN) (flist_lookup (fences, INSN) != NULL)
859
860/* Marks loop as being considered for pipelining.  */
861#define MARK_LOOP_FOR_PIPELINING(LOOP) ((LOOP)->aux = (void *)(size_t)(1))
862#define LOOP_MARKED_FOR_PIPELINING_P(LOOP) ((size_t)((LOOP)->aux))
863
864/* Saved loop preheader to transfer when scheduling the loop.  */
865#define LOOP_PREHEADER_BLOCKS(LOOP) ((size_t)((LOOP)->aux) == 1         \
866                                     ? NULL                             \
867                                     : ((vec<basic_block> *) (LOOP)->aux))
868#define SET_LOOP_PREHEADER_BLOCKS(LOOP,BLOCKS) ((LOOP)->aux             \
869                                                = (BLOCKS != NULL       \
870                                                   ? BLOCKS             \
871                                                   : (LOOP)->aux))
872
873extern bitmap blocks_to_reschedule;
874
875
876/* A variable to track which part of rtx we are scanning in
877   sched-deps.c: sched_analyze_insn ().  */
878enum deps_where_t
879{
880  DEPS_IN_INSN,
881  DEPS_IN_LHS,
882  DEPS_IN_RHS,
883  DEPS_IN_NOWHERE
884};
885
886
887/* Per basic block data for the whole CFG.  */
888struct sel_global_bb_info_def
889{
890  /* For each bb header this field contains a set of live registers.
891     For all other insns this field has a NULL.
892     We also need to know LV sets for the instructions, that are immediately
893     after the border of the region.  */
894  regset lv_set;
895
896  /* Status of LV_SET.
897     true - block has usable LV_SET.
898     false - block's LV_SET should be recomputed.  */
899  bool lv_set_valid_p;
900};
901
902typedef sel_global_bb_info_def *sel_global_bb_info_t;
903
904
905/* Per basic block data.  This array is indexed by basic block index.  */
906extern vec<sel_global_bb_info_def> sel_global_bb_info;
907
908extern void sel_extend_global_bb_info (void);
909extern void sel_finish_global_bb_info (void);
910
911/* Get data for BB.  */
912#define SEL_GLOBAL_BB_INFO(BB)					\
913  (&sel_global_bb_info[(BB)->index])
914
915/* Access macros.  */
916#define BB_LV_SET(BB) (SEL_GLOBAL_BB_INFO (BB)->lv_set)
917#define BB_LV_SET_VALID_P(BB) (SEL_GLOBAL_BB_INFO (BB)->lv_set_valid_p)
918
919/* Per basic block data for the region.  */
920struct sel_region_bb_info_def
921{
922  /* This insn stream is constructed in such a way that it should be
923     traversed by PREV_INSN field - (*not* NEXT_INSN).  */
924  rtx_insn *note_list;
925
926  /* Cached availability set at the beginning of a block.
927     See also AV_LEVEL () for conditions when this av_set can be used.  */
928  av_set_t av_set;
929
930  /* If (AV_LEVEL == GLOBAL_LEVEL) then AV is valid.  */
931  int av_level;
932};
933
934typedef sel_region_bb_info_def *sel_region_bb_info_t;
935
936
937/* Per basic block data.  This array is indexed by basic block index.  */
938extern vec<sel_region_bb_info_def> sel_region_bb_info;
939
940/* Get data for BB.  */
941#define SEL_REGION_BB_INFO(BB) (&sel_region_bb_info[(BB)->index])
942
943/* Get BB's note_list.
944   A note_list is a list of various notes that was scattered across BB
945   before scheduling, and will be appended at the beginning of BB after
946   scheduling is finished.  */
947#define BB_NOTE_LIST(BB) (SEL_REGION_BB_INFO (BB)->note_list)
948
949#define BB_AV_SET(BB) (SEL_REGION_BB_INFO (BB)->av_set)
950#define BB_AV_LEVEL(BB) (SEL_REGION_BB_INFO (BB)->av_level)
951#define BB_AV_SET_VALID_P(BB) (BB_AV_LEVEL (BB) == global_level)
952
953/* Used in bb_in_ebb_p.  */
954extern bitmap_head *forced_ebb_heads;
955
956/* The loop nest being pipelined.  */
957extern class loop *current_loop_nest;
958
959/* Saves pipelined blocks.  Bitmap is indexed by bb->index.  */
960extern sbitmap bbs_pipelined;
961
962/* Various flags.  */
963extern bool enable_moveup_set_path_p;
964extern bool pipelining_p;
965extern bool bookkeeping_p;
966extern int max_insns_to_rename;
967extern bool preheader_removed;
968
969/* Software lookahead window size.
970   According to the results in Nakatani and Ebcioglu [1993], window size of 16
971   is enough to extract most ILP in integer code.  */
972#define MAX_WS (param_selsched_max_lookahead)
973
974extern regset sel_all_regs;
975
976
977/* Successor iterator backend.  */
978struct succ_iterator
979{
980  /* True if we're at BB end.  */
981  bool bb_end;
982
983  /* An edge on which we're iterating.  */
984  edge e1;
985
986  /* The previous edge saved after skipping empty blocks.  */
987  edge e2;
988
989  /* Edge iterator used when there are successors in other basic blocks.  */
990  edge_iterator ei;
991
992  /* Successor block we're traversing.  */
993  basic_block bb;
994
995  /* Flags that are passed to the iterator.  We return only successors
996     that comply to these flags.  */
997  short flags;
998
999  /* When flags include SUCCS_ALL, this will be set to the exact type
1000     of the successor we're traversing now.  */
1001  short current_flags;
1002
1003  /* If skip to loop exits, save here information about loop exits.  */
1004  int current_exit;
1005  vec<edge> loop_exits;
1006};
1007
1008/* A structure returning all successor's information.  */
1009struct succs_info
1010{
1011  /* Flags that these succcessors were computed with.  */
1012  short flags;
1013
1014  /* Successors that correspond to the flags.  */
1015  insn_vec_t succs_ok;
1016
1017  /* Their probabilities.  As of now, we don't need this for other
1018     successors.  */
1019  vec<int> probs_ok;
1020
1021  /* Other successors.  */
1022  insn_vec_t succs_other;
1023
1024  /* Probability of all successors.  */
1025  int all_prob;
1026
1027  /* The number of all successors.  */
1028  int all_succs_n;
1029
1030  /* The number of good successors.  */
1031  int succs_ok_n;
1032};
1033
1034/* Some needed definitions.  */
1035extern basic_block after_recovery;
1036
1037extern rtx_insn *sel_bb_head (basic_block);
1038extern rtx_insn *sel_bb_end (basic_block);
1039extern bool sel_bb_empty_p (basic_block);
1040extern bool in_current_region_p (basic_block);
1041
1042/* True when BB is a header of the inner loop.  */
1043static inline bool
1044inner_loop_header_p (basic_block bb)
1045{
1046  class loop *inner_loop;
1047
1048  if (!current_loop_nest)
1049    return false;
1050
1051  if (bb == EXIT_BLOCK_PTR_FOR_FN (cfun))
1052    return false;
1053
1054  inner_loop = bb->loop_father;
1055  if (inner_loop == current_loop_nest)
1056    return false;
1057
1058  /* If successor belongs to another loop.  */
1059  if (bb == inner_loop->header
1060      && flow_bb_inside_loop_p (current_loop_nest, bb))
1061    {
1062      /* Could be '=' here because of wrong loop depths.  */
1063      gcc_assert (loop_depth (inner_loop) >= loop_depth (current_loop_nest));
1064      return true;
1065    }
1066
1067  return false;
1068}
1069
1070/* Return exit edges of LOOP, filtering out edges with the same dest bb.  */
1071static inline vec<edge>
1072get_loop_exit_edges_unique_dests (const class loop *loop)
1073{
1074  vec<edge> edges = vNULL;
1075  struct loop_exit *exit;
1076
1077  gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)
1078              && current_loops->state & LOOPS_HAVE_RECORDED_EXITS);
1079
1080  for (exit = loop->exits->next; exit->e; exit = exit->next)
1081    {
1082      int i;
1083      edge e;
1084      bool was_dest = false;
1085
1086      for (i = 0; edges.iterate (i, &e); i++)
1087        if (e->dest == exit->e->dest)
1088          {
1089            was_dest = true;
1090            break;
1091          }
1092
1093      if (!was_dest)
1094        edges.safe_push (exit->e);
1095    }
1096  return edges;
1097}
1098
1099static bool
1100sel_bb_empty_or_nop_p (basic_block bb)
1101{
1102  insn_t first = sel_bb_head (bb), last;
1103
1104  if (first == NULL_RTX)
1105    return true;
1106
1107  if (!INSN_NOP_P (first))
1108    return false;
1109
1110  if (bb == EXIT_BLOCK_PTR_FOR_FN (cfun))
1111    return false;
1112
1113  last = sel_bb_end (bb);
1114  if (first != last)
1115    return false;
1116
1117  return true;
1118}
1119
1120/* Collect all loop exits recursively, skipping empty BBs between them.
1121   E.g. if BB is a loop header which has several loop exits,
1122   traverse all of them and if any of them turns out to be another loop header
1123   (after skipping empty BBs), add its loop exits to the resulting vector
1124   as well.  */
1125static inline vec<edge>
1126get_all_loop_exits (basic_block bb)
1127{
1128  vec<edge> exits = vNULL;
1129
1130  /* If bb is empty, and we're skipping to loop exits, then
1131     consider bb as a possible gate to the inner loop now.  */
1132  while (sel_bb_empty_or_nop_p (bb)
1133	 && in_current_region_p (bb)
1134	 && EDGE_COUNT (bb->succs) > 0)
1135    {
1136      bb = single_succ (bb);
1137
1138      /* This empty block could only lead outside the region.  */
1139      gcc_assert (! in_current_region_p (bb));
1140    }
1141
1142  /* And now check whether we should skip over inner loop.  */
1143  if (inner_loop_header_p (bb))
1144    {
1145      class loop *this_loop;
1146      class loop *pred_loop = NULL;
1147      int i;
1148      unsigned this_depth;
1149      edge e;
1150
1151      for (this_loop = bb->loop_father;
1152           this_loop && this_loop != current_loop_nest;
1153           this_loop = loop_outer (this_loop))
1154        pred_loop = this_loop;
1155
1156      this_loop = pred_loop;
1157      gcc_assert (this_loop != NULL);
1158
1159      exits = get_loop_exit_edges_unique_dests (this_loop);
1160      this_depth = loop_depth (this_loop);
1161
1162      /* Traverse all loop headers.  Be careful not to go back
1163	 to the outer loop's header (see PR 84206).  */
1164      for (i = 0; exits.iterate (i, &e); i++)
1165	if ((in_current_region_p (e->dest)
1166	     || (inner_loop_header_p (e->dest)))
1167	    && loop_depth (e->dest->loop_father) >= this_depth)
1168	  {
1169	    vec<edge> next_exits = get_all_loop_exits (e->dest);
1170
1171	    if (next_exits.exists ())
1172	      {
1173		int j;
1174		edge ne;
1175
1176		/* Add all loop exits for the current edge into the
1177		   resulting vector.  */
1178		for (j = 0; next_exits.iterate (j, &ne); j++)
1179		  exits.safe_push (ne);
1180
1181		/* Remove the original edge.  */
1182		exits.ordered_remove (i);
1183
1184		/*  Decrease the loop counter so we won't skip anything.  */
1185		i--;
1186		continue;
1187	      }
1188	  }
1189    }
1190
1191  return exits;
1192}
1193
1194/* Flags to pass to compute_succs_info and FOR_EACH_SUCC.
1195   Any successor will fall into exactly one category.   */
1196
1197/* Include normal successors.  */
1198#define SUCCS_NORMAL (1)
1199
1200/* Include back-edge successors.  */
1201#define SUCCS_BACK (2)
1202
1203/* Include successors that are outside of the current region.  */
1204#define SUCCS_OUT (4)
1205
1206/* When pipelining of the outer loops is enabled, skip innermost loops
1207   to their exits.  */
1208#define SUCCS_SKIP_TO_LOOP_EXITS (8)
1209
1210/* Include all successors.  */
1211#define SUCCS_ALL (SUCCS_NORMAL | SUCCS_BACK | SUCCS_OUT)
1212
1213/* We need to return a succ_iterator to avoid 'unitialized' warning
1214   during bootstrap.  */
1215static inline succ_iterator
1216_succ_iter_start (insn_t *succp, insn_t insn, int flags)
1217{
1218  succ_iterator i;
1219
1220  basic_block bb = BLOCK_FOR_INSN (insn);
1221
1222  gcc_assert (INSN_P (insn) || NOTE_INSN_BASIC_BLOCK_P (insn));
1223
1224  i.flags = flags;
1225
1226  /* Avoid 'uninitialized' warning.  */
1227  *succp = NULL;
1228  i.e1 = NULL;
1229  i.e2 = NULL;
1230  i.bb = bb;
1231  i.current_flags = 0;
1232  i.current_exit = -1;
1233  i.loop_exits.create (0);
1234
1235  if (bb != EXIT_BLOCK_PTR_FOR_FN (cfun) && BB_END (bb) != insn)
1236    {
1237      i.bb_end = false;
1238
1239      /* Avoid 'uninitialized' warning.  */
1240      i.ei.index = 0;
1241      i.ei.container = 0;
1242    }
1243  else
1244    {
1245      i.ei = ei_start (bb->succs);
1246      i.bb_end = true;
1247    }
1248
1249  return i;
1250}
1251
1252static inline bool
1253_succ_iter_cond (succ_iterator *ip, insn_t *succp, insn_t insn,
1254                 bool check (edge, succ_iterator *))
1255{
1256  if (!ip->bb_end)
1257    {
1258      /* When we're in a middle of a basic block, return
1259         the next insn immediately, but only when SUCCS_NORMAL is set.  */
1260      if (*succp != NULL || (ip->flags & SUCCS_NORMAL) == 0)
1261        return false;
1262
1263      *succp = NEXT_INSN (insn);
1264      ip->current_flags = SUCCS_NORMAL;
1265      return true;
1266    }
1267  else
1268    {
1269      while (1)
1270        {
1271          edge e_tmp = NULL;
1272
1273          /* First, try loop exits, if we have them.  */
1274          if (ip->loop_exits.exists ())
1275            {
1276              do
1277                {
1278                  ip->loop_exits.iterate (ip->current_exit, &e_tmp);
1279                  ip->current_exit++;
1280                }
1281	      while (e_tmp && !check (e_tmp, ip));
1282
1283              if (!e_tmp)
1284                ip->loop_exits.release ();
1285            }
1286
1287          /* If we have found a successor, then great.  */
1288          if (e_tmp)
1289            {
1290              ip->e1 = e_tmp;
1291              break;
1292            }
1293
1294          /* If not, then try the next edge.  */
1295          while (ei_cond (ip->ei, &(ip->e1)))
1296            {
1297              basic_block bb = ip->e1->dest;
1298
1299              /* Consider bb as a possible loop header.  */
1300              if ((ip->flags & SUCCS_SKIP_TO_LOOP_EXITS)
1301                  && flag_sel_sched_pipelining_outer_loops
1302		  && (!in_current_region_p (bb)
1303		      || BLOCK_TO_BB (ip->bb->index)
1304			 < BLOCK_TO_BB (bb->index)))
1305                {
1306		  /* Get all loop exits recursively.  */
1307		  ip->loop_exits = get_all_loop_exits (bb);
1308
1309		  if (ip->loop_exits.exists ())
1310		    {
1311  		      ip->current_exit = 0;
1312		      /* Move the iterator now, because we won't do
1313			 succ_iter_next until loop exits will end.  */
1314		      ei_next (&(ip->ei));
1315		      break;
1316		    }
1317                }
1318
1319              /* bb is not a loop header, check as usual.  */
1320              if (check (ip->e1, ip))
1321                break;
1322
1323              ei_next (&(ip->ei));
1324            }
1325
1326          /* If loop_exits are non null, we have found an inner loop;
1327	     do one more iteration to fetch an edge from these exits.  */
1328          if (ip->loop_exits.exists ())
1329            continue;
1330
1331          /* Otherwise, we've found an edge in a usual way.  Break now.  */
1332          break;
1333        }
1334
1335      if (ip->e1)
1336	{
1337	  basic_block bb = ip->e2->dest;
1338
1339	  if (bb == EXIT_BLOCK_PTR_FOR_FN (cfun) || bb == after_recovery)
1340	    *succp = exit_insn;
1341	  else
1342	    {
1343              *succp = sel_bb_head (bb);
1344
1345              gcc_assert (ip->flags != SUCCS_NORMAL
1346                          || *succp == NEXT_INSN (bb_note (bb)));
1347	      gcc_assert (BLOCK_FOR_INSN (*succp) == bb);
1348	    }
1349
1350	  return true;
1351	}
1352      else
1353	return false;
1354    }
1355}
1356
1357static inline void
1358_succ_iter_next (succ_iterator *ip)
1359{
1360  gcc_assert (!ip->e2 || ip->e1);
1361
1362  if (ip->bb_end && ip->e1 && !ip->loop_exits.exists ())
1363    ei_next (&(ip->ei));
1364}
1365
1366/* Returns true when E1 is an eligible successor edge, possibly skipping
1367   empty blocks.  When E2P is not null, the resulting edge is written there.
1368   FLAGS are used to specify whether back edges and out-of-region edges
1369   should be considered.  */
1370static inline bool
1371_eligible_successor_edge_p (edge e1, succ_iterator *ip)
1372{
1373  edge e2 = e1;
1374  basic_block bb;
1375  int flags = ip->flags;
1376  bool src_outside_rgn = !in_current_region_p (e1->src);
1377
1378  gcc_assert (flags != 0);
1379
1380  if (src_outside_rgn)
1381    {
1382      /* Any successor of the block that is outside current region is
1383         ineligible, except when we're skipping to loop exits.  */
1384      gcc_assert (flags & (SUCCS_OUT | SUCCS_SKIP_TO_LOOP_EXITS));
1385
1386      if (flags & SUCCS_OUT)
1387	return false;
1388    }
1389
1390  bb = e2->dest;
1391
1392  /* Skip empty blocks, but be careful not to leave the region.  */
1393  while (1)
1394    {
1395      if (!sel_bb_empty_p (bb))
1396	{
1397	  edge ne;
1398	  basic_block nbb;
1399
1400	  if (!sel_bb_empty_or_nop_p (bb))
1401	    break;
1402
1403	  ne = EDGE_SUCC (bb, 0);
1404	  nbb = ne->dest;
1405
1406	  if (!in_current_region_p (nbb)
1407	      && !(flags & SUCCS_OUT))
1408	    break;
1409
1410	  e2 = ne;
1411	  bb = nbb;
1412	  continue;
1413	}
1414
1415      if (!in_current_region_p (bb)
1416          && !(flags & SUCCS_OUT))
1417        return false;
1418
1419      if (EDGE_COUNT (bb->succs) == 0)
1420	return false;
1421
1422      e2 = EDGE_SUCC (bb, 0);
1423      bb = e2->dest;
1424    }
1425
1426  /* Save the second edge for later checks.  */
1427  ip->e2 = e2;
1428
1429  if (in_current_region_p (bb))
1430    {
1431      /* BLOCK_TO_BB sets topological order of the region here.
1432         It is important to use real predecessor here, which is ip->bb,
1433         as we may well have e1->src outside current region,
1434         when skipping to loop exits.  */
1435      bool succeeds_in_top_order = (BLOCK_TO_BB (ip->bb->index)
1436				    < BLOCK_TO_BB (bb->index));
1437
1438      /* This is true for the all cases except the last one.  */
1439      ip->current_flags = SUCCS_NORMAL;
1440
1441      /* We are advancing forward in the region, as usual.  */
1442      if (succeeds_in_top_order)
1443        {
1444          /* We are skipping to loop exits here.  */
1445          gcc_assert (!src_outside_rgn
1446                      || flag_sel_sched_pipelining_outer_loops);
1447          return !!(flags & SUCCS_NORMAL);
1448        }
1449
1450      /* This is a back edge.  During pipelining we ignore back edges,
1451         but only when it leads to the same loop.  It can lead to the header
1452         of the outer loop, which will also be the preheader of
1453         the current loop.  */
1454      if (pipelining_p
1455           && e1->src->loop_father == bb->loop_father)
1456        return !!(flags & SUCCS_NORMAL);
1457
1458      /* A back edge should be requested explicitly.  */
1459      ip->current_flags = SUCCS_BACK;
1460      return !!(flags & SUCCS_BACK);
1461    }
1462
1463  ip->current_flags = SUCCS_OUT;
1464  return !!(flags & SUCCS_OUT);
1465}
1466
1467#define FOR_EACH_SUCC_1(SUCC, ITER, INSN, FLAGS)                        \
1468  for ((ITER) = _succ_iter_start (&(SUCC), (INSN), (FLAGS));            \
1469       _succ_iter_cond (&(ITER), &(SUCC), (INSN), _eligible_successor_edge_p); \
1470       _succ_iter_next (&(ITER)))
1471
1472#define FOR_EACH_SUCC(SUCC, ITER, INSN)                 \
1473  FOR_EACH_SUCC_1 (SUCC, ITER, INSN, SUCCS_NORMAL)
1474
1475/* Return the current edge along which a successor was built.  */
1476#define SUCC_ITER_EDGE(ITER) ((ITER)->e1)
1477
1478/* Return the next block of BB not running into inconsistencies.  */
1479static inline basic_block
1480bb_next_bb (basic_block bb)
1481{
1482  switch (EDGE_COUNT (bb->succs))
1483    {
1484    case 0:
1485      return bb->next_bb;
1486
1487    case 1:
1488      return single_succ (bb);
1489
1490    case 2:
1491      return FALLTHRU_EDGE (bb)->dest;
1492
1493    default:
1494      return bb->next_bb;
1495    }
1496
1497  gcc_unreachable ();
1498}
1499
1500
1501
1502/* Functions that are used in sel-sched.c.  */
1503
1504/* List functions.  */
1505extern ilist_t ilist_copy (ilist_t);
1506extern ilist_t ilist_invert (ilist_t);
1507extern void blist_add (blist_t *, insn_t, ilist_t, deps_t);
1508extern void blist_remove (blist_t *);
1509extern void flist_tail_init (flist_tail_t);
1510
1511extern fence_t flist_lookup (flist_t, insn_t);
1512extern void flist_clear (flist_t *);
1513extern void def_list_add (def_list_t *, insn_t, unsigned int);
1514
1515/* Target context functions.  */
1516extern tc_t create_target_context (bool);
1517extern void set_target_context (tc_t);
1518extern void reset_target_context (tc_t, bool);
1519
1520/* Deps context functions.  */
1521extern void advance_deps_context (deps_t, insn_t);
1522
1523/* Fences functions.  */
1524extern void init_fences (insn_t);
1525extern void add_clean_fence_to_fences (flist_tail_t, insn_t, fence_t);
1526extern void add_dirty_fence_to_fences (flist_tail_t, insn_t, fence_t);
1527extern void move_fence_to_fences (flist_t, flist_tail_t);
1528
1529/* Pool functions.  */
1530extern regset get_regset_from_pool (void);
1531extern regset get_clear_regset_from_pool (void);
1532extern void return_regset_to_pool (regset);
1533extern void free_regset_pool (void);
1534
1535extern insn_t get_nop_from_pool (insn_t);
1536extern void return_nop_to_pool (insn_t, bool);
1537extern void free_nop_pool (void);
1538
1539/* Vinsns functions.  */
1540extern bool vinsn_separable_p (vinsn_t);
1541extern bool vinsn_cond_branch_p (vinsn_t);
1542extern void recompute_vinsn_lhs_rhs (vinsn_t);
1543extern int sel_vinsn_cost (vinsn_t);
1544extern insn_t sel_gen_insn_from_rtx_after (rtx, expr_t, int, insn_t);
1545extern insn_t sel_gen_recovery_insn_from_rtx_after (rtx, expr_t, int, insn_t);
1546extern insn_t sel_gen_insn_from_expr_after (expr_t, vinsn_t, int, insn_t);
1547extern insn_t  sel_move_insn (expr_t, int, insn_t);
1548extern void vinsn_attach (vinsn_t);
1549extern void vinsn_detach (vinsn_t);
1550extern vinsn_t vinsn_copy (vinsn_t, bool);
1551extern bool vinsn_equal_p (vinsn_t, vinsn_t);
1552
1553/* EXPR functions.  */
1554extern void copy_expr (expr_t, expr_t);
1555extern void copy_expr_onside (expr_t, expr_t);
1556extern void merge_expr_data (expr_t, expr_t, insn_t);
1557extern void merge_expr (expr_t, expr_t, insn_t);
1558extern void clear_expr (expr_t);
1559extern unsigned expr_dest_regno (expr_t);
1560extern rtx expr_dest_reg (expr_t);
1561extern int find_in_history_vect (vec<expr_history_def> ,
1562                                 rtx, vinsn_t, bool);
1563extern void insert_in_history_vect (vec<expr_history_def> *,
1564                                    unsigned, enum local_trans_type,
1565                                    vinsn_t, vinsn_t, ds_t);
1566extern void mark_unavailable_targets (av_set_t, av_set_t, regset);
1567extern int speculate_expr (expr_t, ds_t);
1568
1569/* Av set functions.  */
1570extern void av_set_add (av_set_t *, expr_t);
1571extern void av_set_iter_remove (av_set_iterator *);
1572extern expr_t av_set_lookup (av_set_t, vinsn_t);
1573extern expr_t merge_with_other_exprs (av_set_t *, av_set_iterator *, expr_t);
1574extern bool av_set_is_in_p (av_set_t, vinsn_t);
1575extern av_set_t av_set_copy (av_set_t);
1576extern void av_set_union_and_clear (av_set_t *, av_set_t *, insn_t);
1577extern void av_set_union_and_live (av_set_t *, av_set_t *, regset, regset, insn_t);
1578extern void av_set_clear (av_set_t *);
1579extern void av_set_leave_one_nonspec (av_set_t *);
1580extern expr_t av_set_element (av_set_t, int);
1581extern void av_set_substract_cond_branches (av_set_t *);
1582extern void av_set_split_usefulness (av_set_t, int, int);
1583extern void av_set_code_motion_filter (av_set_t *, av_set_t);
1584
1585extern void sel_save_haifa_priorities (void);
1586
1587extern void sel_init_global_and_expr (bb_vec_t);
1588extern void sel_finish_global_and_expr (void);
1589
1590extern regset compute_live (insn_t);
1591extern bool register_unavailable_p (regset, rtx);
1592
1593/* Dependence analysis functions.  */
1594extern void sel_clear_has_dependence (void);
1595extern ds_t has_dependence_p (expr_t, insn_t, ds_t **);
1596
1597extern int tick_check_p (expr_t, deps_t, fence_t);
1598
1599/* Functions to work with insns.  */
1600extern bool lhs_of_insn_equals_to_dest_p (insn_t, rtx);
1601extern bool insn_eligible_for_subst_p (insn_t);
1602extern void get_dest_and_mode (rtx, rtx *, machine_mode *);
1603
1604extern bool bookkeeping_can_be_created_if_moved_through_p (insn_t);
1605extern bool sel_remove_insn (insn_t, bool, bool);
1606extern bool bb_header_p (insn_t);
1607extern void sel_init_invalid_data_sets (insn_t);
1608extern bool insn_at_boundary_p (insn_t);
1609
1610/* Basic block and CFG functions.  */
1611
1612extern rtx_insn *sel_bb_head (basic_block);
1613extern bool sel_bb_head_p (insn_t);
1614extern rtx_insn *sel_bb_end (basic_block);
1615extern bool sel_bb_end_p (insn_t);
1616extern bool sel_bb_empty_p (basic_block);
1617
1618extern bool in_current_region_p (basic_block);
1619extern basic_block fallthru_bb_of_jump (const rtx_insn *);
1620
1621extern void sel_init_bbs (bb_vec_t);
1622extern void sel_finish_bbs (void);
1623
1624extern struct succs_info * compute_succs_info (insn_t, short);
1625extern void free_succs_info (struct succs_info *);
1626extern bool sel_insn_has_single_succ_p (insn_t, int);
1627extern bool sel_num_cfg_preds_gt_1 (insn_t);
1628extern int get_seqno_by_preds (rtx_insn *);
1629
1630extern bool bb_ends_ebb_p (basic_block);
1631extern bool in_same_ebb_p (insn_t, insn_t);
1632
1633extern bool tidy_control_flow (basic_block, bool);
1634extern void free_bb_note_pool (void);
1635
1636extern void purge_empty_blocks (void);
1637extern basic_block sel_split_edge (edge);
1638extern basic_block sel_create_recovery_block (insn_t);
1639extern bool sel_redirect_edge_and_branch (edge, basic_block);
1640extern void sel_redirect_edge_and_branch_force (edge, basic_block);
1641extern void sel_init_pipelining (void);
1642extern void sel_finish_pipelining (void);
1643extern void sel_sched_region (int);
1644extern loop_p get_loop_nest_for_rgn (unsigned int);
1645extern bool considered_for_pipelining_p (class loop *);
1646extern void make_region_from_loop_preheader (vec<basic_block> *&);
1647extern void sel_add_loop_preheaders (bb_vec_t *);
1648extern bool sel_is_loop_preheader_p (basic_block);
1649extern void clear_outdated_rtx_info (basic_block);
1650extern void free_data_sets (basic_block);
1651extern void exchange_data_sets (basic_block, basic_block);
1652extern void copy_data_sets (basic_block, basic_block);
1653
1654extern void sel_register_cfg_hooks (void);
1655extern void sel_unregister_cfg_hooks (void);
1656
1657/* Expression transformation routines.  */
1658extern rtx_insn *create_insn_rtx_from_pattern (rtx, rtx);
1659extern vinsn_t create_vinsn_from_insn_rtx (rtx_insn *, bool);
1660extern rtx_insn *create_copy_of_insn_rtx (rtx);
1661extern void change_vinsn_in_expr (expr_t, vinsn_t);
1662
1663/* Various initialization functions.  */
1664extern void init_lv_sets (void);
1665extern void free_lv_sets (void);
1666extern void setup_nop_and_exit_insns (void);
1667extern void free_nop_and_exit_insns (void);
1668extern void free_data_for_scheduled_insn (insn_t);
1669extern void setup_nop_vinsn (void);
1670extern void free_nop_vinsn (void);
1671extern void sel_set_sched_flags (void);
1672extern void sel_setup_sched_infos (void);
1673extern void alloc_sched_pools (void);
1674extern void free_sched_pools (void);
1675
1676#endif /* GCC_SEL_SCHED_IR_H */
1677