1 /* Instruction scheduling pass.  This file contains definitions used
2    internally in the scheduler.
3    Copyright (C) 2006-2018 Free Software Foundation, Inc.
4 
5 This file is part of GCC.
6 
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.
11 
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.
16 
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/>.  */
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.  */
29 typedef 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.  */
34 struct _list_node;
35 
36 /* List backend.  */
37 typedef struct _list_node *_list_t;
38 #define _LIST_NEXT(L) ((L)->next)
39 
40 /* Instruction data that is part of vinsn type.  */
41 struct idata_def;
42 typedef struct idata_def *idata_t;
43 
44 /* A virtual instruction, i.e. an instruction as seen by the scheduler.  */
45 struct vinsn_def;
46 typedef struct vinsn_def *vinsn_t;
47 
48 /* RTX list.
49    This type is the backend for ilist.  */
50 typedef _list_t _xlist_t;
51 #define _XLIST_X(L) ((L)->u.x)
52 #define _XLIST_NEXT(L) (_LIST_NEXT (L))
53 
54 /* Instruction.  */
55 typedef rtx_insn *insn_t;
56 
57 /* List of insns.  */
58 typedef _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.  */
64 enum 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.  */
72 struct 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 
90 typedef struct expr_history_def_1 expr_history_def;
91 
92 
93 /* Expression information.  */
94 struct _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 
159 typedef struct _expr expr_def;
160 typedef 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.  */
187 struct _def
188 {
189   insn_t orig_insn;
190 
191   /* FIXME: Get rid of CROSSES_CALL 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 CROSSES_CALL
195      to static params.  */
196   bool crosses_call;
197 };
198 typedef struct _def *def_t;
199 
200 
201 /* Availability sets are sets of expressions we're scheduling.  */
202 typedef _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.  */
208 struct _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 };
227 typedef 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.  */
238 typedef _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.  */
245 struct _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 };
303 typedef 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.  */
324 typedef _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.  */
329 struct flist_tail_def
330 {
331   flist_t head;
332   flist_t *tailp;
333 };
334 
335 typedef 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.  */
340 struct _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.  */
360 extern object_allocator<_list_node> sched_lists_pool;
361 
362 static inline _list_t
363 _list_alloc (void)
364 {
365   return sched_lists_pool.allocate ();
366 }
367 
368 static 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 
377 static inline void
378 _list_remove_nofree (_list_t *lp)
379 {
380   _list_t n = *lp;
381 
382   *lp = _LIST_NEXT (n);
383 }
384 
385 static 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 
394 static inline void
395 _list_clear (_list_t *l)
396 {
397   while (*l)
398     _list_remove (l);
399 }
400 
401 
402 /* List iterator backend.  */
403 struct _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 
415 static 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 
423 static 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 
432 static 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 
440 static 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 
463 static 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 
473 static 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.  */
487 static 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 
501 typedef _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 
508 static inline void
509 ilist_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 
517 static inline bool
518 ilist_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.  */
531 static 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 
545 typedef _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.  */
551 typedef _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 
555 inline 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.  */
569 typedef _list_t def_list_t;
570 typedef _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 
577 static 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.  */
591 struct 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.  */
647 struct 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.  */
693 struct 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.  */
716 struct _sel_insn_data
717 {
718   /* The expression that contains vinsn for this insn and some
719      flow-sensitive data like priority.  */
720   expr_def expr;
721 
722   /* If (WS_LEVEL == GLOBAL_LEVEL) then AV is empty.  */
723   int ws_level;
724 
725   /* A number that helps in defining a traversing order for a region.  */
726   int seqno;
727 
728   /* A liveness data computed above this insn.  */
729   regset live;
730 
731   /* An INSN_UID bit is set when deps analysis result is already known.  */
732   bitmap analyzed_deps;
733 
734   /* An INSN_UID bit is set when a hard dep was found, not set when
735      no dependence is found.  This is meaningful only when the analyzed_deps
736      bitmap has its bit set.  */
737   bitmap found_deps;
738 
739   /* An INSN_UID bit is set when this is a bookkeeping insn generated from
740      a parent with this uid.  If a parent is a bookkeeping copy, all its
741      originators are transitively included in this set.  */
742   bitmap originators;
743 
744   /* A hashtable caching the result of insn transformations through this one.  */
745   htab_t transformed_insns;
746 
747   /* A context incapsulating this insn.  */
748   struct deps_desc deps_context;
749 
750   /* This field is initialized at the beginning of scheduling and is used
751      to handle sched group instructions.  If it is non-null, then it points
752      to the instruction, which should be forced to schedule next.  Such
753      instructions are unique.  */
754   insn_t sched_next;
755 
756   /* Cycle at which insn was scheduled.  It is greater than zero if insn was
757      scheduled.  This is used for bundling.  */
758   int sched_cycle;
759 
760   /* Cycle at which insn's data will be fully ready.  */
761   int ready_cycle;
762 
763   /* Speculations that are being checked by this insn.  */
764   ds_t spec_checked_ds;
765 
766   /* Whether the live set valid or not.  */
767   BOOL_BITFIELD live_valid_p : 1;
768   /* Insn is an ASM.  */
769   BOOL_BITFIELD asm_p : 1;
770 
771   /* True when an insn is scheduled after we've determined that a stall is
772      required.
773      This is used when emulating the Haifa scheduler for bundling.  */
774   BOOL_BITFIELD after_stall_p : 1;
775 };
776 
777 typedef struct _sel_insn_data sel_insn_data_def;
778 typedef sel_insn_data_def *sel_insn_data_t;
779 
780 extern vec<sel_insn_data_def> s_i_d;
781 
782 /* Accessor macros for s_i_d.  */
783 #define SID(INSN) (&s_i_d[INSN_LUID (INSN)])
784 #define SID_BY_UID(UID) (&s_i_d[LUID_BY_UID (UID)])
785 
786 extern sel_insn_data_def insn_sid (insn_t);
787 
788 #define INSN_ASM_P(INSN) (SID (INSN)->asm_p)
789 #define INSN_SCHED_NEXT(INSN) (SID (INSN)->sched_next)
790 #define INSN_ANALYZED_DEPS(INSN) (SID (INSN)->analyzed_deps)
791 #define INSN_FOUND_DEPS(INSN) (SID (INSN)->found_deps)
792 #define INSN_DEPS_CONTEXT(INSN) (SID (INSN)->deps_context)
793 #define INSN_ORIGINATORS(INSN) (SID (INSN)->originators)
794 #define INSN_ORIGINATORS_BY_UID(UID) (SID_BY_UID (UID)->originators)
795 #define INSN_TRANSFORMED_INSNS(INSN) (SID (INSN)->transformed_insns)
796 
797 #define INSN_EXPR(INSN) (&SID (INSN)->expr)
798 #define INSN_LIVE(INSN) (SID (INSN)->live)
799 #define INSN_LIVE_VALID_P(INSN) (SID (INSN)->live_valid_p)
800 #define INSN_VINSN(INSN) (EXPR_VINSN (INSN_EXPR (INSN)))
801 #define INSN_TYPE(INSN) (VINSN_TYPE (INSN_VINSN (INSN)))
802 #define INSN_SIMPLEJUMP_P(INSN) (INSN_TYPE (INSN) == PC)
803 #define INSN_LHS(INSN) (VINSN_LHS (INSN_VINSN (INSN)))
804 #define INSN_RHS(INSN) (VINSN_RHS (INSN_VINSN (INSN)))
805 #define INSN_REG_SETS(INSN) (VINSN_REG_SETS (INSN_VINSN (INSN)))
806 #define INSN_REG_CLOBBERS(INSN) (VINSN_REG_CLOBBERS (INSN_VINSN (INSN)))
807 #define INSN_REG_USES(INSN) (VINSN_REG_USES (INSN_VINSN (INSN)))
808 #define INSN_SCHED_TIMES(INSN) (EXPR_SCHED_TIMES (INSN_EXPR (INSN)))
809 #define INSN_SEQNO(INSN) (SID (INSN)->seqno)
810 #define INSN_AFTER_STALL_P(INSN) (SID (INSN)->after_stall_p)
811 #define INSN_SCHED_CYCLE(INSN) (SID (INSN)->sched_cycle)
812 #define INSN_READY_CYCLE(INSN) (SID (INSN)->ready_cycle)
813 #define INSN_SPEC_CHECKED_DS(INSN) (SID (INSN)->spec_checked_ds)
814 
815 /* A global level shows whether an insn is valid or not.  */
816 extern int global_level;
817 
818 #define INSN_WS_LEVEL(INSN) (SID (INSN)->ws_level)
819 
820 extern av_set_t get_av_set (insn_t);
821 extern int get_av_level (insn_t);
822 
823 #define AV_SET(INSN) (get_av_set (INSN))
824 #define AV_LEVEL(INSN) (get_av_level (INSN))
825 #define AV_SET_VALID_P(INSN) (AV_LEVEL (INSN) == global_level)
826 
827 /* A list of fences currently in the works.  */
828 extern flist_t fences;
829 
830 /* A NOP pattern used as a placeholder for real insns.  */
831 extern rtx nop_pattern;
832 
833 /* An insn that 'contained' in EXIT block.  */
834 extern rtx_insn *exit_insn;
835 
836 /* Provide a separate luid for the insn.  */
837 #define INSN_INIT_TODO_LUID (1)
838 
839 /* Initialize s_s_i_d.  */
840 #define INSN_INIT_TODO_SSID (2)
841 
842 /* Initialize data for simplejump.  */
843 #define INSN_INIT_TODO_SIMPLEJUMP (4)
844 
845 /* Return true if INSN is a local NOP.  The nop is local in the sense that
846    it was emitted by the scheduler as a temporary insn and will soon be
847    deleted.  These nops are identified by their pattern.  */
848 #define INSN_NOP_P(INSN) (PATTERN (INSN) == nop_pattern)
849 
850 /* Return true if INSN is linked into instruction stream.
851    NB: It is impossible for INSN to have one field null and the other not
852    null: gcc_assert ((PREV_INSN (INSN) == NULL_RTX)
853    == (NEXT_INSN (INSN) == NULL_RTX)) is valid.  */
854 #define INSN_IN_STREAM_P(INSN) (PREV_INSN (INSN) && NEXT_INSN (INSN))
855 
856 /* Return true if INSN is in current fence.  */
857 #define IN_CURRENT_FENCE_P(INSN) (flist_lookup (fences, INSN) != NULL)
858 
859 /* Marks loop as being considered for pipelining.  */
860 #define MARK_LOOP_FOR_PIPELINING(LOOP) ((LOOP)->aux = (void *)(size_t)(1))
861 #define LOOP_MARKED_FOR_PIPELINING_P(LOOP) ((size_t)((LOOP)->aux))
862 
863 /* Saved loop preheader to transfer when scheduling the loop.  */
864 #define LOOP_PREHEADER_BLOCKS(LOOP) ((size_t)((LOOP)->aux) == 1         \
865                                      ? NULL                             \
866                                      : ((vec<basic_block> *) (LOOP)->aux))
867 #define SET_LOOP_PREHEADER_BLOCKS(LOOP,BLOCKS) ((LOOP)->aux             \
868                                                 = (BLOCKS != NULL       \
869                                                    ? BLOCKS             \
870                                                    : (LOOP)->aux))
871 
872 extern bitmap blocks_to_reschedule;
873 
874 
875 /* A variable to track which part of rtx we are scanning in
876    sched-deps.c: sched_analyze_insn ().  */
877 enum deps_where_t
878 {
879   DEPS_IN_INSN,
880   DEPS_IN_LHS,
881   DEPS_IN_RHS,
882   DEPS_IN_NOWHERE
883 };
884 
885 
886 /* Per basic block data for the whole CFG.  */
887 struct sel_global_bb_info_def
888 {
889   /* For each bb header this field contains a set of live registers.
890      For all other insns this field has a NULL.
891      We also need to know LV sets for the instructions, that are immediately
892      after the border of the region.  */
893   regset lv_set;
894 
895   /* Status of LV_SET.
896      true - block has usable LV_SET.
897      false - block's LV_SET should be recomputed.  */
898   bool lv_set_valid_p;
899 };
900 
901 typedef sel_global_bb_info_def *sel_global_bb_info_t;
902 
903 
904 /* Per basic block data.  This array is indexed by basic block index.  */
905 extern vec<sel_global_bb_info_def> sel_global_bb_info;
906 
907 extern void sel_extend_global_bb_info (void);
908 extern void sel_finish_global_bb_info (void);
909 
910 /* Get data for BB.  */
911 #define SEL_GLOBAL_BB_INFO(BB)					\
912   (&sel_global_bb_info[(BB)->index])
913 
914 /* Access macros.  */
915 #define BB_LV_SET(BB) (SEL_GLOBAL_BB_INFO (BB)->lv_set)
916 #define BB_LV_SET_VALID_P(BB) (SEL_GLOBAL_BB_INFO (BB)->lv_set_valid_p)
917 
918 /* Per basic block data for the region.  */
919 struct sel_region_bb_info_def
920 {
921   /* This insn stream is constructed in such a way that it should be
922      traversed by PREV_INSN field - (*not* NEXT_INSN).  */
923   rtx_insn *note_list;
924 
925   /* Cached availability set at the beginning of a block.
926      See also AV_LEVEL () for conditions when this av_set can be used.  */
927   av_set_t av_set;
928 
929   /* If (AV_LEVEL == GLOBAL_LEVEL) then AV is valid.  */
930   int av_level;
931 };
932 
933 typedef sel_region_bb_info_def *sel_region_bb_info_t;
934 
935 
936 /* Per basic block data.  This array is indexed by basic block index.  */
937 extern vec<sel_region_bb_info_def> sel_region_bb_info;
938 
939 /* Get data for BB.  */
940 #define SEL_REGION_BB_INFO(BB) (&sel_region_bb_info[(BB)->index])
941 
942 /* Get BB's note_list.
943    A note_list is a list of various notes that was scattered across BB
944    before scheduling, and will be appended at the beginning of BB after
945    scheduling is finished.  */
946 #define BB_NOTE_LIST(BB) (SEL_REGION_BB_INFO (BB)->note_list)
947 
948 #define BB_AV_SET(BB) (SEL_REGION_BB_INFO (BB)->av_set)
949 #define BB_AV_LEVEL(BB) (SEL_REGION_BB_INFO (BB)->av_level)
950 #define BB_AV_SET_VALID_P(BB) (BB_AV_LEVEL (BB) == global_level)
951 
952 /* Used in bb_in_ebb_p.  */
953 extern bitmap_head *forced_ebb_heads;
954 
955 /* The loop nest being pipelined.  */
956 extern struct loop *current_loop_nest;
957 
958 /* Saves pipelined blocks.  Bitmap is indexed by bb->index.  */
959 extern sbitmap bbs_pipelined;
960 
961 /* Various flags.  */
962 extern bool enable_moveup_set_path_p;
963 extern bool pipelining_p;
964 extern bool bookkeeping_p;
965 extern int max_insns_to_rename;
966 extern bool preheader_removed;
967 
968 /* Software lookahead window size.
969    According to the results in Nakatani and Ebcioglu [1993], window size of 16
970    is enough to extract most ILP in integer code.  */
971 #define MAX_WS (PARAM_VALUE (PARAM_SELSCHED_MAX_LOOKAHEAD))
972 
973 extern regset sel_all_regs;
974 
975 
976 /* Successor iterator backend.  */
977 struct succ_iterator
978 {
979   /* True if we're at BB end.  */
980   bool bb_end;
981 
982   /* An edge on which we're iterating.  */
983   edge e1;
984 
985   /* The previous edge saved after skipping empty blocks.  */
986   edge e2;
987 
988   /* Edge iterator used when there are successors in other basic blocks.  */
989   edge_iterator ei;
990 
991   /* Successor block we're traversing.  */
992   basic_block bb;
993 
994   /* Flags that are passed to the iterator.  We return only successors
995      that comply to these flags.  */
996   short flags;
997 
998   /* When flags include SUCCS_ALL, this will be set to the exact type
999      of the successor we're traversing now.  */
1000   short current_flags;
1001 
1002   /* If skip to loop exits, save here information about loop exits.  */
1003   int current_exit;
1004   vec<edge> loop_exits;
1005 };
1006 
1007 /* A structure returning all successor's information.  */
1008 struct succs_info
1009 {
1010   /* Flags that these succcessors were computed with.  */
1011   short flags;
1012 
1013   /* Successors that correspond to the flags.  */
1014   insn_vec_t succs_ok;
1015 
1016   /* Their probabilities.  As of now, we don't need this for other
1017      successors.  */
1018   vec<int> probs_ok;
1019 
1020   /* Other successors.  */
1021   insn_vec_t succs_other;
1022 
1023   /* Probability of all successors.  */
1024   int all_prob;
1025 
1026   /* The number of all successors.  */
1027   int all_succs_n;
1028 
1029   /* The number of good successors.  */
1030   int succs_ok_n;
1031 };
1032 
1033 /* Some needed definitions.  */
1034 extern basic_block after_recovery;
1035 
1036 extern rtx_insn *sel_bb_head (basic_block);
1037 extern rtx_insn *sel_bb_end (basic_block);
1038 extern bool sel_bb_empty_p (basic_block);
1039 extern bool in_current_region_p (basic_block);
1040 
1041 /* True when BB is a header of the inner loop.  */
1042 static inline bool
1043 inner_loop_header_p (basic_block bb)
1044 {
1045   struct loop *inner_loop;
1046 
1047   if (!current_loop_nest)
1048     return false;
1049 
1050   if (bb == EXIT_BLOCK_PTR_FOR_FN (cfun))
1051     return false;
1052 
1053   inner_loop = bb->loop_father;
1054   if (inner_loop == current_loop_nest)
1055     return false;
1056 
1057   /* If successor belongs to another loop.  */
1058   if (bb == inner_loop->header
1059       && flow_bb_inside_loop_p (current_loop_nest, bb))
1060     {
1061       /* Could be '=' here because of wrong loop depths.  */
1062       gcc_assert (loop_depth (inner_loop) >= loop_depth (current_loop_nest));
1063       return true;
1064     }
1065 
1066   return false;
1067 }
1068 
1069 /* Return exit edges of LOOP, filtering out edges with the same dest bb.  */
1070 static inline vec<edge>
1071 get_loop_exit_edges_unique_dests (const struct loop *loop)
1072 {
1073   vec<edge> edges = vNULL;
1074   struct loop_exit *exit;
1075 
1076   gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)
1077               && current_loops->state & LOOPS_HAVE_RECORDED_EXITS);
1078 
1079   for (exit = loop->exits->next; exit->e; exit = exit->next)
1080     {
1081       int i;
1082       edge e;
1083       bool was_dest = false;
1084 
1085       for (i = 0; edges.iterate (i, &e); i++)
1086         if (e->dest == exit->e->dest)
1087           {
1088             was_dest = true;
1089             break;
1090           }
1091 
1092       if (!was_dest)
1093         edges.safe_push (exit->e);
1094     }
1095   return edges;
1096 }
1097 
1098 static bool
1099 sel_bb_empty_or_nop_p (basic_block bb)
1100 {
1101   insn_t first = sel_bb_head (bb), last;
1102 
1103   if (first == NULL_RTX)
1104     return true;
1105 
1106   if (!INSN_NOP_P (first))
1107     return false;
1108 
1109   if (bb == EXIT_BLOCK_PTR_FOR_FN (cfun))
1110     return false;
1111 
1112   last = sel_bb_end (bb);
1113   if (first != last)
1114     return false;
1115 
1116   return true;
1117 }
1118 
1119 /* Collect all loop exits recursively, skipping empty BBs between them.
1120    E.g. if BB is a loop header which has several loop exits,
1121    traverse all of them and if any of them turns out to be another loop header
1122    (after skipping empty BBs), add its loop exits to the resulting vector
1123    as well.  */
1124 static inline vec<edge>
1125 get_all_loop_exits (basic_block bb)
1126 {
1127   vec<edge> exits = vNULL;
1128 
1129   /* If bb is empty, and we're skipping to loop exits, then
1130      consider bb as a possible gate to the inner loop now.  */
1131   while (sel_bb_empty_or_nop_p (bb)
1132 	 && in_current_region_p (bb)
1133 	 && EDGE_COUNT (bb->succs) > 0)
1134     {
1135       bb = single_succ (bb);
1136 
1137       /* This empty block could only lead outside the region.  */
1138       gcc_assert (! in_current_region_p (bb));
1139     }
1140 
1141   /* And now check whether we should skip over inner loop.  */
1142   if (inner_loop_header_p (bb))
1143     {
1144       struct loop *this_loop;
1145       struct loop *pred_loop = NULL;
1146       int i;
1147       edge e;
1148 
1149       for (this_loop = bb->loop_father;
1150            this_loop && this_loop != current_loop_nest;
1151            this_loop = loop_outer (this_loop))
1152         pred_loop = this_loop;
1153 
1154       this_loop = pred_loop;
1155       gcc_assert (this_loop != NULL);
1156 
1157       exits = get_loop_exit_edges_unique_dests (this_loop);
1158 
1159       /* Traverse all loop headers.  */
1160       for (i = 0; exits.iterate (i, &e); i++)
1161 	if (in_current_region_p (e->dest)
1162 	    || inner_loop_header_p (e->dest))
1163 	  {
1164 	    vec<edge> next_exits = get_all_loop_exits (e->dest);
1165 
1166 	    if (next_exits.exists ())
1167 	      {
1168 		int j;
1169 		edge ne;
1170 
1171 		/* Add all loop exits for the current edge into the
1172 		   resulting vector.  */
1173 		for (j = 0; next_exits.iterate (j, &ne); j++)
1174 		  exits.safe_push (ne);
1175 
1176 		/* Remove the original edge.  */
1177 		exits.ordered_remove (i);
1178 
1179 		/*  Decrease the loop counter so we won't skip anything.  */
1180 		i--;
1181 		continue;
1182 	      }
1183 	  }
1184     }
1185 
1186   return exits;
1187 }
1188 
1189 /* Flags to pass to compute_succs_info and FOR_EACH_SUCC.
1190    Any successor will fall into exactly one category.   */
1191 
1192 /* Include normal successors.  */
1193 #define SUCCS_NORMAL (1)
1194 
1195 /* Include back-edge successors.  */
1196 #define SUCCS_BACK (2)
1197 
1198 /* Include successors that are outside of the current region.  */
1199 #define SUCCS_OUT (4)
1200 
1201 /* When pipelining of the outer loops is enabled, skip innermost loops
1202    to their exits.  */
1203 #define SUCCS_SKIP_TO_LOOP_EXITS (8)
1204 
1205 /* Include all successors.  */
1206 #define SUCCS_ALL (SUCCS_NORMAL | SUCCS_BACK | SUCCS_OUT)
1207 
1208 /* We need to return a succ_iterator to avoid 'unitialized' warning
1209    during bootstrap.  */
1210 static inline succ_iterator
1211 _succ_iter_start (insn_t *succp, insn_t insn, int flags)
1212 {
1213   succ_iterator i;
1214 
1215   basic_block bb = BLOCK_FOR_INSN (insn);
1216 
1217   gcc_assert (INSN_P (insn) || NOTE_INSN_BASIC_BLOCK_P (insn));
1218 
1219   i.flags = flags;
1220 
1221   /* Avoid 'uninitialized' warning.  */
1222   *succp = NULL;
1223   i.e1 = NULL;
1224   i.e2 = NULL;
1225   i.bb = bb;
1226   i.current_flags = 0;
1227   i.current_exit = -1;
1228   i.loop_exits.create (0);
1229 
1230   if (bb != EXIT_BLOCK_PTR_FOR_FN (cfun) && BB_END (bb) != insn)
1231     {
1232       i.bb_end = false;
1233 
1234       /* Avoid 'uninitialized' warning.  */
1235       i.ei.index = 0;
1236       i.ei.container = 0;
1237     }
1238   else
1239     {
1240       i.ei = ei_start (bb->succs);
1241       i.bb_end = true;
1242     }
1243 
1244   return i;
1245 }
1246 
1247 static inline bool
1248 _succ_iter_cond (succ_iterator *ip, insn_t *succp, insn_t insn,
1249                  bool check (edge, succ_iterator *))
1250 {
1251   if (!ip->bb_end)
1252     {
1253       /* When we're in a middle of a basic block, return
1254          the next insn immediately, but only when SUCCS_NORMAL is set.  */
1255       if (*succp != NULL || (ip->flags & SUCCS_NORMAL) == 0)
1256         return false;
1257 
1258       *succp = NEXT_INSN (insn);
1259       ip->current_flags = SUCCS_NORMAL;
1260       return true;
1261     }
1262   else
1263     {
1264       while (1)
1265         {
1266           edge e_tmp = NULL;
1267 
1268           /* First, try loop exits, if we have them.  */
1269           if (ip->loop_exits.exists ())
1270             {
1271               do
1272                 {
1273                   ip->loop_exits.iterate (ip->current_exit, &e_tmp);
1274                   ip->current_exit++;
1275                 }
1276 	      while (e_tmp && !check (e_tmp, ip));
1277 
1278               if (!e_tmp)
1279                 ip->loop_exits.release ();
1280             }
1281 
1282           /* If we have found a successor, then great.  */
1283           if (e_tmp)
1284             {
1285               ip->e1 = e_tmp;
1286               break;
1287             }
1288 
1289           /* If not, then try the next edge.  */
1290           while (ei_cond (ip->ei, &(ip->e1)))
1291             {
1292               basic_block bb = ip->e1->dest;
1293 
1294               /* Consider bb as a possible loop header.  */
1295               if ((ip->flags & SUCCS_SKIP_TO_LOOP_EXITS)
1296                   && flag_sel_sched_pipelining_outer_loops
1297 		  && (!in_current_region_p (bb)
1298 		      || BLOCK_TO_BB (ip->bb->index)
1299 			 < BLOCK_TO_BB (bb->index)))
1300                 {
1301 		  /* Get all loop exits recursively.  */
1302 		  ip->loop_exits = get_all_loop_exits (bb);
1303 
1304 		  if (ip->loop_exits.exists ())
1305 		    {
1306   		      ip->current_exit = 0;
1307 		      /* Move the iterator now, because we won't do
1308 			 succ_iter_next until loop exits will end.  */
1309 		      ei_next (&(ip->ei));
1310 		      break;
1311 		    }
1312                 }
1313 
1314               /* bb is not a loop header, check as usual.  */
1315               if (check (ip->e1, ip))
1316                 break;
1317 
1318               ei_next (&(ip->ei));
1319             }
1320 
1321           /* If loop_exits are non null, we have found an inner loop;
1322 	     do one more iteration to fetch an edge from these exits.  */
1323           if (ip->loop_exits.exists ())
1324             continue;
1325 
1326           /* Otherwise, we've found an edge in a usual way.  Break now.  */
1327           break;
1328         }
1329 
1330       if (ip->e1)
1331 	{
1332 	  basic_block bb = ip->e2->dest;
1333 
1334 	  if (bb == EXIT_BLOCK_PTR_FOR_FN (cfun) || bb == after_recovery)
1335 	    *succp = exit_insn;
1336 	  else
1337 	    {
1338               *succp = sel_bb_head (bb);
1339 
1340               gcc_assert (ip->flags != SUCCS_NORMAL
1341                           || *succp == NEXT_INSN (bb_note (bb)));
1342 	      gcc_assert (BLOCK_FOR_INSN (*succp) == bb);
1343 	    }
1344 
1345 	  return true;
1346 	}
1347       else
1348 	return false;
1349     }
1350 }
1351 
1352 static inline void
1353 _succ_iter_next (succ_iterator *ip)
1354 {
1355   gcc_assert (!ip->e2 || ip->e1);
1356 
1357   if (ip->bb_end && ip->e1 && !ip->loop_exits.exists ())
1358     ei_next (&(ip->ei));
1359 }
1360 
1361 /* Returns true when E1 is an eligible successor edge, possibly skipping
1362    empty blocks.  When E2P is not null, the resulting edge is written there.
1363    FLAGS are used to specify whether back edges and out-of-region edges
1364    should be considered.  */
1365 static inline bool
1366 _eligible_successor_edge_p (edge e1, succ_iterator *ip)
1367 {
1368   edge e2 = e1;
1369   basic_block bb;
1370   int flags = ip->flags;
1371   bool src_outside_rgn = !in_current_region_p (e1->src);
1372 
1373   gcc_assert (flags != 0);
1374 
1375   if (src_outside_rgn)
1376     {
1377       /* Any successor of the block that is outside current region is
1378          ineligible, except when we're skipping to loop exits.  */
1379       gcc_assert (flags & (SUCCS_OUT | SUCCS_SKIP_TO_LOOP_EXITS));
1380 
1381       if (flags & SUCCS_OUT)
1382 	return false;
1383     }
1384 
1385   bb = e2->dest;
1386 
1387   /* Skip empty blocks, but be careful not to leave the region.  */
1388   while (1)
1389     {
1390       if (!sel_bb_empty_p (bb))
1391 	{
1392 	  edge ne;
1393 	  basic_block nbb;
1394 
1395 	  if (!sel_bb_empty_or_nop_p (bb))
1396 	    break;
1397 
1398 	  ne = EDGE_SUCC (bb, 0);
1399 	  nbb = ne->dest;
1400 
1401 	  if (!in_current_region_p (nbb)
1402 	      && !(flags & SUCCS_OUT))
1403 	    break;
1404 
1405 	  e2 = ne;
1406 	  bb = nbb;
1407 	  continue;
1408 	}
1409 
1410       if (!in_current_region_p (bb)
1411           && !(flags & SUCCS_OUT))
1412         return false;
1413 
1414       if (EDGE_COUNT (bb->succs) == 0)
1415 	return false;
1416 
1417       e2 = EDGE_SUCC (bb, 0);
1418       bb = e2->dest;
1419     }
1420 
1421   /* Save the second edge for later checks.  */
1422   ip->e2 = e2;
1423 
1424   if (in_current_region_p (bb))
1425     {
1426       /* BLOCK_TO_BB sets topological order of the region here.
1427          It is important to use real predecessor here, which is ip->bb,
1428          as we may well have e1->src outside current region,
1429          when skipping to loop exits.  */
1430       bool succeeds_in_top_order = (BLOCK_TO_BB (ip->bb->index)
1431 				    < BLOCK_TO_BB (bb->index));
1432 
1433       /* This is true for the all cases except the last one.  */
1434       ip->current_flags = SUCCS_NORMAL;
1435 
1436       /* We are advancing forward in the region, as usual.  */
1437       if (succeeds_in_top_order)
1438         {
1439           /* We are skipping to loop exits here.  */
1440           gcc_assert (!src_outside_rgn
1441                       || flag_sel_sched_pipelining_outer_loops);
1442           return !!(flags & SUCCS_NORMAL);
1443         }
1444 
1445       /* This is a back edge.  During pipelining we ignore back edges,
1446          but only when it leads to the same loop.  It can lead to the header
1447          of the outer loop, which will also be the preheader of
1448          the current loop.  */
1449       if (pipelining_p
1450            && e1->src->loop_father == bb->loop_father)
1451         return !!(flags & SUCCS_NORMAL);
1452 
1453       /* A back edge should be requested explicitly.  */
1454       ip->current_flags = SUCCS_BACK;
1455       return !!(flags & SUCCS_BACK);
1456     }
1457 
1458   ip->current_flags = SUCCS_OUT;
1459   return !!(flags & SUCCS_OUT);
1460 }
1461 
1462 #define FOR_EACH_SUCC_1(SUCC, ITER, INSN, FLAGS)                        \
1463   for ((ITER) = _succ_iter_start (&(SUCC), (INSN), (FLAGS));            \
1464        _succ_iter_cond (&(ITER), &(SUCC), (INSN), _eligible_successor_edge_p); \
1465        _succ_iter_next (&(ITER)))
1466 
1467 #define FOR_EACH_SUCC(SUCC, ITER, INSN)                 \
1468   FOR_EACH_SUCC_1 (SUCC, ITER, INSN, SUCCS_NORMAL)
1469 
1470 /* Return the current edge along which a successor was built.  */
1471 #define SUCC_ITER_EDGE(ITER) ((ITER)->e1)
1472 
1473 /* Return the next block of BB not running into inconsistencies.  */
1474 static inline basic_block
1475 bb_next_bb (basic_block bb)
1476 {
1477   switch (EDGE_COUNT (bb->succs))
1478     {
1479     case 0:
1480       return bb->next_bb;
1481 
1482     case 1:
1483       return single_succ (bb);
1484 
1485     case 2:
1486       return FALLTHRU_EDGE (bb)->dest;
1487 
1488     default:
1489       return bb->next_bb;
1490     }
1491 
1492   gcc_unreachable ();
1493 }
1494 
1495 
1496 
1497 /* Functions that are used in sel-sched.c.  */
1498 
1499 /* List functions.  */
1500 extern ilist_t ilist_copy (ilist_t);
1501 extern ilist_t ilist_invert (ilist_t);
1502 extern void blist_add (blist_t *, insn_t, ilist_t, deps_t);
1503 extern void blist_remove (blist_t *);
1504 extern void flist_tail_init (flist_tail_t);
1505 
1506 extern fence_t flist_lookup (flist_t, insn_t);
1507 extern void flist_clear (flist_t *);
1508 extern void def_list_add (def_list_t *, insn_t, bool);
1509 
1510 /* Target context functions.  */
1511 extern tc_t create_target_context (bool);
1512 extern void set_target_context (tc_t);
1513 extern void reset_target_context (tc_t, bool);
1514 
1515 /* Deps context functions.  */
1516 extern void advance_deps_context (deps_t, insn_t);
1517 
1518 /* Fences functions.  */
1519 extern void init_fences (insn_t);
1520 extern void add_clean_fence_to_fences (flist_tail_t, insn_t, fence_t);
1521 extern void add_dirty_fence_to_fences (flist_tail_t, insn_t, fence_t);
1522 extern void move_fence_to_fences (flist_t, flist_tail_t);
1523 
1524 /* Pool functions.  */
1525 extern regset get_regset_from_pool (void);
1526 extern regset get_clear_regset_from_pool (void);
1527 extern void return_regset_to_pool (regset);
1528 extern void free_regset_pool (void);
1529 
1530 extern insn_t get_nop_from_pool (insn_t);
1531 extern void return_nop_to_pool (insn_t, bool);
1532 extern void free_nop_pool (void);
1533 
1534 /* Vinsns functions.  */
1535 extern bool vinsn_separable_p (vinsn_t);
1536 extern bool vinsn_cond_branch_p (vinsn_t);
1537 extern void recompute_vinsn_lhs_rhs (vinsn_t);
1538 extern int sel_vinsn_cost (vinsn_t);
1539 extern insn_t sel_gen_insn_from_rtx_after (rtx, expr_t, int, insn_t);
1540 extern insn_t sel_gen_recovery_insn_from_rtx_after (rtx, expr_t, int, insn_t);
1541 extern insn_t sel_gen_insn_from_expr_after (expr_t, vinsn_t, int, insn_t);
1542 extern insn_t  sel_move_insn (expr_t, int, insn_t);
1543 extern void vinsn_attach (vinsn_t);
1544 extern void vinsn_detach (vinsn_t);
1545 extern vinsn_t vinsn_copy (vinsn_t, bool);
1546 extern bool vinsn_equal_p (vinsn_t, vinsn_t);
1547 
1548 /* EXPR functions.  */
1549 extern void copy_expr (expr_t, expr_t);
1550 extern void copy_expr_onside (expr_t, expr_t);
1551 extern void merge_expr_data (expr_t, expr_t, insn_t);
1552 extern void merge_expr (expr_t, expr_t, insn_t);
1553 extern void clear_expr (expr_t);
1554 extern unsigned expr_dest_regno (expr_t);
1555 extern rtx expr_dest_reg (expr_t);
1556 extern int find_in_history_vect (vec<expr_history_def> ,
1557                                  rtx, vinsn_t, bool);
1558 extern void insert_in_history_vect (vec<expr_history_def> *,
1559                                     unsigned, enum local_trans_type,
1560                                     vinsn_t, vinsn_t, ds_t);
1561 extern void mark_unavailable_targets (av_set_t, av_set_t, regset);
1562 extern int speculate_expr (expr_t, ds_t);
1563 
1564 /* Av set functions.  */
1565 extern void av_set_add (av_set_t *, expr_t);
1566 extern void av_set_iter_remove (av_set_iterator *);
1567 extern expr_t av_set_lookup (av_set_t, vinsn_t);
1568 extern expr_t merge_with_other_exprs (av_set_t *, av_set_iterator *, expr_t);
1569 extern bool av_set_is_in_p (av_set_t, vinsn_t);
1570 extern av_set_t av_set_copy (av_set_t);
1571 extern void av_set_union_and_clear (av_set_t *, av_set_t *, insn_t);
1572 extern void av_set_union_and_live (av_set_t *, av_set_t *, regset, regset, insn_t);
1573 extern void av_set_clear (av_set_t *);
1574 extern void av_set_leave_one_nonspec (av_set_t *);
1575 extern expr_t av_set_element (av_set_t, int);
1576 extern void av_set_substract_cond_branches (av_set_t *);
1577 extern void av_set_split_usefulness (av_set_t, int, int);
1578 extern void av_set_code_motion_filter (av_set_t *, av_set_t);
1579 
1580 extern void sel_save_haifa_priorities (void);
1581 
1582 extern void sel_init_global_and_expr (bb_vec_t);
1583 extern void sel_finish_global_and_expr (void);
1584 
1585 extern regset compute_live (insn_t);
1586 extern bool register_unavailable_p (regset, rtx);
1587 
1588 /* Dependence analysis functions.  */
1589 extern void sel_clear_has_dependence (void);
1590 extern ds_t has_dependence_p (expr_t, insn_t, ds_t **);
1591 
1592 extern int tick_check_p (expr_t, deps_t, fence_t);
1593 
1594 /* Functions to work with insns.  */
1595 extern bool lhs_of_insn_equals_to_dest_p (insn_t, rtx);
1596 extern bool insn_eligible_for_subst_p (insn_t);
1597 extern void get_dest_and_mode (rtx, rtx *, machine_mode *);
1598 
1599 extern bool bookkeeping_can_be_created_if_moved_through_p (insn_t);
1600 extern bool sel_remove_insn (insn_t, bool, bool);
1601 extern bool bb_header_p (insn_t);
1602 extern void sel_init_invalid_data_sets (insn_t);
1603 extern bool insn_at_boundary_p (insn_t);
1604 
1605 /* Basic block and CFG functions.  */
1606 
1607 extern rtx_insn *sel_bb_head (basic_block);
1608 extern bool sel_bb_head_p (insn_t);
1609 extern rtx_insn *sel_bb_end (basic_block);
1610 extern bool sel_bb_end_p (insn_t);
1611 extern bool sel_bb_empty_p (basic_block);
1612 
1613 extern bool in_current_region_p (basic_block);
1614 extern basic_block fallthru_bb_of_jump (const rtx_insn *);
1615 
1616 extern void sel_init_bbs (bb_vec_t);
1617 extern void sel_finish_bbs (void);
1618 
1619 extern struct succs_info * compute_succs_info (insn_t, short);
1620 extern void free_succs_info (struct succs_info *);
1621 extern bool sel_insn_has_single_succ_p (insn_t, int);
1622 extern bool sel_num_cfg_preds_gt_1 (insn_t);
1623 extern int get_seqno_by_preds (rtx_insn *);
1624 
1625 extern bool bb_ends_ebb_p (basic_block);
1626 extern bool in_same_ebb_p (insn_t, insn_t);
1627 
1628 extern bool tidy_control_flow (basic_block, bool);
1629 extern void free_bb_note_pool (void);
1630 
1631 extern void purge_empty_blocks (void);
1632 extern basic_block sel_split_edge (edge);
1633 extern basic_block sel_create_recovery_block (insn_t);
1634 extern bool sel_redirect_edge_and_branch (edge, basic_block);
1635 extern void sel_redirect_edge_and_branch_force (edge, basic_block);
1636 extern void sel_init_pipelining (void);
1637 extern void sel_finish_pipelining (void);
1638 extern void sel_sched_region (int);
1639 extern loop_p get_loop_nest_for_rgn (unsigned int);
1640 extern bool considered_for_pipelining_p (struct loop *);
1641 extern void make_region_from_loop_preheader (vec<basic_block> *&);
1642 extern void sel_add_loop_preheaders (bb_vec_t *);
1643 extern bool sel_is_loop_preheader_p (basic_block);
1644 extern void clear_outdated_rtx_info (basic_block);
1645 extern void free_data_sets (basic_block);
1646 extern void exchange_data_sets (basic_block, basic_block);
1647 extern void copy_data_sets (basic_block, basic_block);
1648 
1649 extern void sel_register_cfg_hooks (void);
1650 extern void sel_unregister_cfg_hooks (void);
1651 
1652 /* Expression transformation routines.  */
1653 extern rtx_insn *create_insn_rtx_from_pattern (rtx, rtx);
1654 extern vinsn_t create_vinsn_from_insn_rtx (rtx_insn *, bool);
1655 extern rtx_insn *create_copy_of_insn_rtx (rtx);
1656 extern void change_vinsn_in_expr (expr_t, vinsn_t);
1657 
1658 /* Various initialization functions.  */
1659 extern void init_lv_sets (void);
1660 extern void free_lv_sets (void);
1661 extern void setup_nop_and_exit_insns (void);
1662 extern void free_nop_and_exit_insns (void);
1663 extern void free_data_for_scheduled_insn (insn_t);
1664 extern void setup_nop_vinsn (void);
1665 extern void free_nop_vinsn (void);
1666 extern void sel_set_sched_flags (void);
1667 extern void sel_setup_sched_infos (void);
1668 extern void alloc_sched_pools (void);
1669 extern void free_sched_pools (void);
1670 
1671 #endif /* GCC_SEL_SCHED_IR_H */
1672