1 /* Instruction scheduling pass.  This file contains definitions used
2    internally in the scheduler.
3    Copyright (C) 1992-2014 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_SCHED_INT_H
22 #define GCC_SCHED_INT_H
23 
24 #include "insn-attr.h"
25 
26 #ifdef INSN_SCHEDULING
27 
28 #include "df.h"
29 #include "basic-block.h"
30 
31 /* Identificator of a scheduler pass.  */
32 enum sched_pass_id_t { SCHED_PASS_UNKNOWN, SCHED_RGN_PASS, SCHED_EBB_PASS,
33 		       SCHED_SMS_PASS, SCHED_SEL_PASS };
34 
35 /* The algorithm used to implement -fsched-pressure.  */
36 enum sched_pressure_algorithm
37 {
38   SCHED_PRESSURE_NONE,
39   SCHED_PRESSURE_WEIGHTED,
40   SCHED_PRESSURE_MODEL
41 };
42 
43 typedef vec<basic_block> bb_vec_t;
44 typedef vec<rtx> insn_vec_t;
45 typedef vec<rtx> rtx_vec_t;
46 
47 extern void sched_init_bbs (void);
48 
49 extern void sched_extend_luids (void);
50 extern void sched_init_insn_luid (rtx);
51 extern void sched_init_luids (bb_vec_t);
52 extern void sched_finish_luids (void);
53 
54 extern void sched_extend_target (void);
55 
56 extern void haifa_init_h_i_d (bb_vec_t);
57 extern void haifa_finish_h_i_d (void);
58 
59 /* Hooks that are common to all the schedulers.  */
60 struct common_sched_info_def
61 {
62   /* Called after blocks were rearranged due to movement of jump instruction.
63      The first parameter - index of basic block, in which jump currently is.
64      The second parameter - index of basic block, in which jump used
65      to be.
66      The third parameter - index of basic block, that follows the second
67      parameter.  */
68   void (*fix_recovery_cfg) (int, int, int);
69 
70   /* Called to notify frontend, that new basic block is being added.
71      The first parameter - new basic block.
72      The second parameter - block, after which new basic block is being added,
73      or the exit block, if recovery block is being added,
74      or NULL, if standalone block is being added.  */
75   void (*add_block) (basic_block, basic_block);
76 
77   /* Estimate number of insns in the basic block.  */
78   int (*estimate_number_of_insns) (basic_block);
79 
80   /* Given a non-insn (!INSN_P (x)) return
81      -1 - if this rtx don't need a luid.
82      0 - if it should have the same luid as the previous insn.
83      1 - if it needs a separate luid.  */
84   int (*luid_for_non_insn) (rtx);
85 
86   /* Scheduler pass identifier.  It is preferably used in assertions.  */
87   enum sched_pass_id_t sched_pass_id;
88 };
89 
90 extern struct common_sched_info_def *common_sched_info;
91 
92 extern const struct common_sched_info_def haifa_common_sched_info;
93 
94 /* Return true if selective scheduling pass is working.  */
95 static inline bool
sel_sched_p(void)96 sel_sched_p (void)
97 {
98   return common_sched_info->sched_pass_id == SCHED_SEL_PASS;
99 }
100 
101 /* Returns maximum priority that an insn was assigned to.  */
102 extern int get_rgn_sched_max_insns_priority (void);
103 
104 /* Increases effective priority for INSN by AMOUNT.  */
105 extern void sel_add_to_insn_priority (rtx, int);
106 
107 /* True if during selective scheduling we need to emulate some of haifa
108    scheduler behaviour.  */
109 extern int sched_emulate_haifa_p;
110 
111 /* Mapping from INSN_UID to INSN_LUID.  In the end all other per insn data
112    structures should be indexed by luid.  */
113 extern vec<int> sched_luids;
114 #define INSN_LUID(INSN) (sched_luids[INSN_UID (INSN)])
115 #define LUID_BY_UID(UID) (sched_luids[UID])
116 
117 #define SET_INSN_LUID(INSN, LUID) \
118 (sched_luids[INSN_UID (INSN)] = (LUID))
119 
120 /* The highest INSN_LUID.  */
121 extern int sched_max_luid;
122 
123 extern int insn_luid (rtx);
124 
125 /* This list holds ripped off notes from the current block.  These notes will
126    be attached to the beginning of the block when its scheduling is
127    finished.  */
128 extern rtx note_list;
129 
130 extern void remove_notes (rtx, rtx);
131 extern rtx restore_other_notes (rtx, basic_block);
132 extern void sched_insns_init (rtx);
133 extern void sched_insns_finish (void);
134 
135 extern void *xrecalloc (void *, size_t, size_t, size_t);
136 
137 extern void reemit_notes (rtx);
138 
139 /* Functions in haifa-sched.c.  */
140 extern int haifa_classify_insn (const_rtx);
141 
142 /* Functions in sel-sched-ir.c.  */
143 extern void sel_find_rgns (void);
144 extern void sel_mark_hard_insn (rtx);
145 
146 extern size_t dfa_state_size;
147 
148 extern void advance_state (state_t);
149 
150 extern void setup_sched_dump (void);
151 extern void sched_init (void);
152 extern void sched_finish (void);
153 
154 extern bool sel_insn_is_speculation_check (rtx);
155 
156 /* Describe the ready list of the scheduler.
157    VEC holds space enough for all insns in the current region.  VECLEN
158    says how many exactly.
159    FIRST is the index of the element with the highest priority; i.e. the
160    last one in the ready list, since elements are ordered by ascending
161    priority.
162    N_READY determines how many insns are on the ready list.
163    N_DEBUG determines how many debug insns are on the ready list.  */
164 struct ready_list
165 {
166   rtx *vec;
167   int veclen;
168   int first;
169   int n_ready;
170   int n_debug;
171 };
172 
173 extern char *ready_try;
174 extern struct ready_list ready;
175 
176 extern int max_issue (struct ready_list *, int, state_t, bool, int *);
177 
178 extern void ebb_compute_jump_reg_dependencies (rtx, regset);
179 
180 extern edge find_fallthru_edge_from (basic_block);
181 
182 extern void (* sched_init_only_bb) (basic_block, basic_block);
183 extern basic_block (* sched_split_block) (basic_block, rtx);
184 extern basic_block sched_split_block_1 (basic_block, rtx);
185 extern basic_block (* sched_create_empty_bb) (basic_block);
186 extern basic_block sched_create_empty_bb_1 (basic_block);
187 
188 extern basic_block sched_create_recovery_block (basic_block *);
189 extern void sched_create_recovery_edges (basic_block, basic_block,
190 					 basic_block);
191 
192 /* Pointer to data describing the current DFA state.  */
193 extern state_t curr_state;
194 
195 /* Type to represent status of a dependence.  */
196 typedef unsigned int ds_t;
197 #define BITS_PER_DEP_STATUS HOST_BITS_PER_INT
198 
199 /* Type to represent weakness of speculative dependence.  */
200 typedef unsigned int dw_t;
201 
202 extern enum reg_note ds_to_dk (ds_t);
203 extern ds_t dk_to_ds (enum reg_note);
204 
205 /* Describe a dependency that can be broken by making a replacement
206    in one of the patterns.  LOC is the location, ORIG and NEWVAL the
207    two alternative contents, and INSN the instruction that must be
208    changed.  */
209 struct dep_replacement
210 {
211   rtx *loc;
212   rtx orig;
213   rtx newval;
214   rtx insn;
215 };
216 
217 /* Information about the dependency.  */
218 struct _dep
219 {
220   /* Producer.  */
221   rtx pro;
222 
223   /* Consumer.  */
224   rtx con;
225 
226   /* If nonnull, holds a pointer to information about how to break the
227      dependency by making a replacement in one of the insns.  There is
228      only one such dependency for each insn that must be modified in
229      order to break such a dependency.  */
230   struct dep_replacement *replace;
231 
232   /* Dependency status.  This field holds all dependency types and additional
233      information for speculative dependencies.  */
234   ds_t status;
235 
236   /* Dependency major type.  This field is superseded by STATUS above.
237      Though, it is still in place because some targets use it.  */
238   ENUM_BITFIELD(reg_note) type:6;
239 
240   unsigned nonreg:1;
241   unsigned multiple:1;
242 
243   /* Cached cost of the dependency.  Make sure to update UNKNOWN_DEP_COST
244      when changing the size of this field.  */
245   int cost:20;
246 };
247 
248 #define UNKNOWN_DEP_COST (-1<<19)
249 
250 typedef struct _dep dep_def;
251 typedef dep_def *dep_t;
252 
253 #define DEP_PRO(D) ((D)->pro)
254 #define DEP_CON(D) ((D)->con)
255 #define DEP_TYPE(D) ((D)->type)
256 #define DEP_STATUS(D) ((D)->status)
257 #define DEP_COST(D) ((D)->cost)
258 #define DEP_NONREG(D) ((D)->nonreg)
259 #define DEP_MULTIPLE(D) ((D)->multiple)
260 #define DEP_REPLACE(D) ((D)->replace)
261 
262 /* Functions to work with dep.  */
263 
264 extern void init_dep_1 (dep_t, rtx, rtx, enum reg_note, ds_t);
265 extern void init_dep (dep_t, rtx, rtx, enum reg_note);
266 
267 extern void sd_debug_dep (dep_t);
268 
269 /* Definition of this struct resides below.  */
270 struct _dep_node;
271 typedef struct _dep_node *dep_node_t;
272 
273 /* A link in the dependency list.  This is essentially an equivalent of a
274    single {INSN, DEPS}_LIST rtx.  */
275 struct _dep_link
276 {
277   /* Dep node with all the data.  */
278   dep_node_t node;
279 
280   /* Next link in the list. For the last one it is NULL.  */
281   struct _dep_link *next;
282 
283   /* Pointer to the next field of the previous link in the list.
284      For the first link this points to the deps_list->first.
285 
286      With help of this field it is easy to remove and insert links to the
287      list.  */
288   struct _dep_link **prev_nextp;
289 };
290 typedef struct _dep_link *dep_link_t;
291 
292 #define DEP_LINK_NODE(N) ((N)->node)
293 #define DEP_LINK_NEXT(N) ((N)->next)
294 #define DEP_LINK_PREV_NEXTP(N) ((N)->prev_nextp)
295 
296 /* Macros to work dep_link.  For most usecases only part of the dependency
297    information is need.  These macros conveniently provide that piece of
298    information.  */
299 
300 #define DEP_LINK_DEP(N) (DEP_NODE_DEP (DEP_LINK_NODE (N)))
301 #define DEP_LINK_PRO(N) (DEP_PRO (DEP_LINK_DEP (N)))
302 #define DEP_LINK_CON(N) (DEP_CON (DEP_LINK_DEP (N)))
303 #define DEP_LINK_TYPE(N) (DEP_TYPE (DEP_LINK_DEP (N)))
304 #define DEP_LINK_STATUS(N) (DEP_STATUS (DEP_LINK_DEP (N)))
305 
306 /* A list of dep_links.  */
307 struct _deps_list
308 {
309   /* First element.  */
310   dep_link_t first;
311 
312   /* Total number of elements in the list.  */
313   int n_links;
314 };
315 typedef struct _deps_list *deps_list_t;
316 
317 #define DEPS_LIST_FIRST(L) ((L)->first)
318 #define DEPS_LIST_N_LINKS(L) ((L)->n_links)
319 
320 /* Suppose we have a dependence Y between insn pro1 and con1, where pro1 has
321    additional dependents con0 and con2, and con1 is dependent on additional
322    insns pro0 and pro1:
323 
324    .con0      pro0
325    . ^         |
326    . |         |
327    . |         |
328    . X         A
329    . |         |
330    . |         |
331    . |         V
332    .pro1--Y-->con1
333    . |         ^
334    . |         |
335    . |         |
336    . Z         B
337    . |         |
338    . |         |
339    . V         |
340    .con2      pro2
341 
342    This is represented using a "dep_node" for each dependence arc, which are
343    connected as follows (diagram is centered around Y which is fully shown;
344    other dep_nodes shown partially):
345 
346    .          +------------+    +--------------+    +------------+
347    .          : dep_node X :    |  dep_node Y  |    : dep_node Z :
348    .          :            :    |              |    :            :
349    .          :            :    |              |    :            :
350    .          : forw       :    |  forw        |    : forw       :
351    .          : +--------+ :    |  +--------+  |    : +--------+ :
352    forw_deps  : |dep_link| :    |  |dep_link|  |    : |dep_link| :
353    +-----+    : | +----+ | :    |  | +----+ |  |    : | +----+ | :
354    |first|----->| |next|-+------+->| |next|-+--+----->| |next|-+--->NULL
355    +-----+    : | +----+ | :    |  | +----+ |  |    : | +----+ | :
356    . ^  ^     : |     ^  | :    |  |     ^  |  |    : |        | :
357    . |  |     : |     |  | :    |  |     |  |  |    : |        | :
358    . |  +--<----+--+  +--+---<--+--+--+  +--+--+--<---+--+     | :
359    . |        : |  |     | :    |  |  |     |  |    : |  |     | :
360    . |        : | +----+ | :    |  | +----+ |  |    : | +----+ | :
361    . |        : | |prev| | :    |  | |prev| |  |    : | |prev| | :
362    . |        : | |next| | :    |  | |next| |  |    : | |next| | :
363    . |        : | +----+ | :    |  | +----+ |  |    : | +----+ | :
364    . |        : |        | :<-+ |  |        |  |<-+ : |        | :<-+
365    . |        : | +----+ | :  | |  | +----+ |  |  | : | +----+ | :  |
366    . |        : | |node|-+----+ |  | |node|-+--+--+ : | |node|-+----+
367    . |        : | +----+ | :    |  | +----+ |  |    : | +----+ | :
368    . |        : |        | :    |  |        |  |    : |        | :
369    . |        : +--------+ :    |  +--------+  |    : +--------+ :
370    . |        :            :    |              |    :            :
371    . |        :  SAME pro1 :    |  +--------+  |    :  SAME pro1 :
372    . |        :  DIFF con0 :    |  |dep     |  |    :  DIFF con2 :
373    . |        :            :    |  |        |  |    :            :
374    . |                          |  | +----+ |  |
375    .RTX<------------------------+--+-|pro1| |  |
376    .pro1                        |  | +----+ |  |
377    .                            |  |        |  |
378    .                            |  | +----+ |  |
379    .RTX<------------------------+--+-|con1| |  |
380    .con1                        |  | +----+ |  |
381    . |                          |  |        |  |
382    . |                          |  | +----+ |  |
383    . |                          |  | |kind| |  |
384    . |                          |  | +----+ |  |
385    . |        :            :    |  | |stat| |  |    :            :
386    . |        :  DIFF pro0 :    |  | +----+ |  |    :  DIFF pro2 :
387    . |        :  SAME con1 :    |  |        |  |    :  SAME con1 :
388    . |        :            :    |  +--------+  |    :            :
389    . |        :            :    |              |    :            :
390    . |        : back       :    |  back        |    : back       :
391    . v        : +--------+ :    |  +--------+  |    : +--------+ :
392    back_deps  : |dep_link| :    |  |dep_link|  |    : |dep_link| :
393    +-----+    : | +----+ | :    |  | +----+ |  |    : | +----+ | :
394    |first|----->| |next|-+------+->| |next|-+--+----->| |next|-+--->NULL
395    +-----+    : | +----+ | :    |  | +----+ |  |    : | +----+ | :
396    .    ^     : |     ^  | :    |  |     ^  |  |    : |        | :
397    .    |     : |     |  | :    |  |     |  |  |    : |        | :
398    .    +--<----+--+  +--+---<--+--+--+  +--+--+--<---+--+     | :
399    .          : |  |     | :    |  |  |     |  |    : |  |     | :
400    .          : | +----+ | :    |  | +----+ |  |    : | +----+ | :
401    .          : | |prev| | :    |  | |prev| |  |    : | |prev| | :
402    .          : | |next| | :    |  | |next| |  |    : | |next| | :
403    .          : | +----+ | :    |  | +----+ |  |    : | +----+ | :
404    .          : |        | :<-+ |  |        |  |<-+ : |        | :<-+
405    .          : | +----+ | :  | |  | +----+ |  |  | : | +----+ | :  |
406    .          : | |node|-+----+ |  | |node|-+--+--+ : | |node|-+----+
407    .          : | +----+ | :    |  | +----+ |  |    : | +----+ | :
408    .          : |        | :    |  |        |  |    : |        | :
409    .          : +--------+ :    |  +--------+  |    : +--------+ :
410    .          :            :    |              |    :            :
411    .          : dep_node A :    |  dep_node Y  |    : dep_node B :
412    .          +------------+    +--------------+    +------------+
413 */
414 
415 struct _dep_node
416 {
417   /* Backward link.  */
418   struct _dep_link back;
419 
420   /* The dep.  */
421   struct _dep dep;
422 
423   /* Forward link.  */
424   struct _dep_link forw;
425 };
426 
427 #define DEP_NODE_BACK(N) (&(N)->back)
428 #define DEP_NODE_DEP(N) (&(N)->dep)
429 #define DEP_NODE_FORW(N) (&(N)->forw)
430 
431 /* The following enumeration values tell us what dependencies we
432    should use to implement the barrier.  We use true-dependencies for
433    TRUE_BARRIER and anti-dependencies for MOVE_BARRIER.  */
434 enum reg_pending_barrier_mode
435 {
436   NOT_A_BARRIER = 0,
437   MOVE_BARRIER,
438   TRUE_BARRIER
439 };
440 
441 /* Whether a register movement is associated with a call.  */
442 enum post_call_group
443 {
444   not_post_call,
445   post_call,
446   post_call_initial
447 };
448 
449 /* Insns which affect pseudo-registers.  */
450 struct deps_reg
451 {
452   rtx uses;
453   rtx sets;
454   rtx implicit_sets;
455   rtx control_uses;
456   rtx clobbers;
457   int uses_length;
458   int clobbers_length;
459 };
460 
461 /* Describe state of dependencies used during sched_analyze phase.  */
462 struct deps_desc
463 {
464   /* The *_insns and *_mems are paired lists.  Each pending memory operation
465      will have a pointer to the MEM rtx on one list and a pointer to the
466      containing insn on the other list in the same place in the list.  */
467 
468   /* We can't use add_dependence like the old code did, because a single insn
469      may have multiple memory accesses, and hence needs to be on the list
470      once for each memory access.  Add_dependence won't let you add an insn
471      to a list more than once.  */
472 
473   /* An INSN_LIST containing all insns with pending read operations.  */
474   rtx pending_read_insns;
475 
476   /* An EXPR_LIST containing all MEM rtx's which are pending reads.  */
477   rtx pending_read_mems;
478 
479   /* An INSN_LIST containing all insns with pending write operations.  */
480   rtx pending_write_insns;
481 
482   /* An EXPR_LIST containing all MEM rtx's which are pending writes.  */
483   rtx pending_write_mems;
484 
485   /* An INSN_LIST containing all jump insns.  */
486   rtx pending_jump_insns;
487 
488   /* We must prevent the above lists from ever growing too large since
489      the number of dependencies produced is at least O(N*N),
490      and execution time is at least O(4*N*N), as a function of the
491      length of these pending lists.  */
492 
493   /* Indicates the length of the pending_read list.  */
494   int pending_read_list_length;
495 
496   /* Indicates the length of the pending_write list.  */
497   int pending_write_list_length;
498 
499   /* Length of the pending memory flush list plus the length of the pending
500      jump insn list.  Large functions with no calls may build up extremely
501      large lists.  */
502   int pending_flush_length;
503 
504   /* The last insn upon which all memory references must depend.
505      This is an insn which flushed the pending lists, creating a dependency
506      between it and all previously pending memory references.  This creates
507      a barrier (or a checkpoint) which no memory reference is allowed to cross.
508 
509      This includes all non constant CALL_INSNs.  When we do interprocedural
510      alias analysis, this restriction can be relaxed.
511      This may also be an INSN that writes memory if the pending lists grow
512      too large.  */
513   rtx last_pending_memory_flush;
514 
515   /* A list of the last function calls we have seen.  We use a list to
516      represent last function calls from multiple predecessor blocks.
517      Used to prevent register lifetimes from expanding unnecessarily.  */
518   rtx last_function_call;
519 
520   /* A list of the last function calls that may not return normally
521      we have seen.  We use a list to represent last function calls from
522      multiple predecessor blocks.  Used to prevent moving trapping insns
523      across such calls.  */
524   rtx last_function_call_may_noreturn;
525 
526   /* A list of insns which use a pseudo register that does not already
527      cross a call.  We create dependencies between each of those insn
528      and the next call insn, to ensure that they won't cross a call after
529      scheduling is done.  */
530   rtx sched_before_next_call;
531 
532   /* Similarly, a list of insns which should not cross a branch.  */
533   rtx sched_before_next_jump;
534 
535   /* Used to keep post-call pseudo/hard reg movements together with
536      the call.  */
537   enum post_call_group in_post_call_group_p;
538 
539   /* The last debug insn we've seen.  */
540   rtx last_debug_insn;
541 
542   /* The last insn bearing REG_ARGS_SIZE that we've seen.  */
543   rtx last_args_size;
544 
545   /* The maximum register number for the following arrays.  Before reload
546      this is max_reg_num; after reload it is FIRST_PSEUDO_REGISTER.  */
547   int max_reg;
548 
549   /* Element N is the next insn that sets (hard or pseudo) register
550      N within the current basic block; or zero, if there is no
551      such insn.  Needed for new registers which may be introduced
552      by splitting insns.  */
553   struct deps_reg *reg_last;
554 
555   /* Element N is set for each register that has any nonzero element
556      in reg_last[N].{uses,sets,clobbers}.  */
557   regset_head reg_last_in_use;
558 
559   /* Shows the last value of reg_pending_barrier associated with the insn.  */
560   enum reg_pending_barrier_mode last_reg_pending_barrier;
561 
562   /* True when this context should be treated as a readonly by
563      the analysis.  */
564   BOOL_BITFIELD readonly : 1;
565 };
566 
567 typedef struct deps_desc *deps_t;
568 
569 /* This structure holds some state of the current scheduling pass, and
570    contains some function pointers that abstract out some of the non-generic
571    functionality from functions such as schedule_block or schedule_insn.
572    There is one global variable, current_sched_info, which points to the
573    sched_info structure currently in use.  */
574 struct haifa_sched_info
575 {
576   /* Add all insns that are initially ready to the ready list.  Called once
577      before scheduling a set of insns.  */
578   void (*init_ready_list) (void);
579   /* Called after taking an insn from the ready list.  Returns nonzero if
580      this insn can be scheduled, nonzero if we should silently discard it.  */
581   int (*can_schedule_ready_p) (rtx);
582   /* Return nonzero if there are more insns that should be scheduled.  */
583   int (*schedule_more_p) (void);
584   /* Called after an insn has all its hard dependencies resolved.
585      Adjusts status of instruction (which is passed through second parameter)
586      to indicate if instruction should be moved to the ready list or the
587      queue, or if it should silently discard it (until next resolved
588      dependence).  */
589   ds_t (*new_ready) (rtx, ds_t);
590   /* Compare priority of two insns.  Return a positive number if the second
591      insn is to be preferred for scheduling, and a negative one if the first
592      is to be preferred.  Zero if they are equally good.  */
593   int (*rank) (rtx, rtx);
594   /* Return a string that contains the insn uid and optionally anything else
595      necessary to identify this insn in an output.  It's valid to use a
596      static buffer for this.  The ALIGNED parameter should cause the string
597      to be formatted so that multiple output lines will line up nicely.  */
598   const char *(*print_insn) (const_rtx, int);
599   /* Return nonzero if an insn should be included in priority
600      calculations.  */
601   int (*contributes_to_priority) (rtx, rtx);
602 
603   /* Return true if scheduling insn (passed as the parameter) will trigger
604      finish of scheduling current block.  */
605   bool (*insn_finishes_block_p) (rtx);
606 
607   /* The boundaries of the set of insns to be scheduled.  */
608   rtx prev_head, next_tail;
609 
610   /* Filled in after the schedule is finished; the first and last scheduled
611      insns.  */
612   rtx head, tail;
613 
614   /* If nonzero, enables an additional sanity check in schedule_block.  */
615   unsigned int queue_must_finish_empty:1;
616 
617   /* Maximum priority that has been assigned to an insn.  */
618   int sched_max_insns_priority;
619 
620   /* Hooks to support speculative scheduling.  */
621 
622   /* Called to notify frontend that instruction is being added (second
623      parameter == 0) or removed (second parameter == 1).  */
624   void (*add_remove_insn) (rtx, int);
625 
626   /* Called to notify the frontend that instruction INSN is being
627      scheduled.  */
628   void (*begin_schedule_ready) (rtx insn);
629 
630   /* Called to notify the frontend that an instruction INSN is about to be
631      moved to its correct place in the final schedule.  This is done for all
632      insns in order of the schedule.  LAST indicates the last scheduled
633      instruction.  */
634   void (*begin_move_insn) (rtx insn, rtx last);
635 
636   /* If the second parameter is not NULL, return nonnull value, if the
637      basic block should be advanced.
638      If the second parameter is NULL, return the next basic block in EBB.
639      The first parameter is the current basic block in EBB.  */
640   basic_block (*advance_target_bb) (basic_block, rtx);
641 
642   /* Allocate memory, store the frontend scheduler state in it, and
643      return it.  */
644   void *(*save_state) (void);
645   /* Restore frontend scheduler state from the argument, and free the
646      memory.  */
647   void (*restore_state) (void *);
648 
649   /* ??? FIXME: should use straight bitfields inside sched_info instead of
650      this flag field.  */
651   unsigned int flags;
652 };
653 
654 /* This structure holds description of the properties for speculative
655    scheduling.  */
656 struct spec_info_def
657 {
658   /* Holds types of allowed speculations: BEGIN_{DATA|CONTROL},
659      BE_IN_{DATA_CONTROL}.  */
660   int mask;
661 
662   /* A dump file for additional information on speculative scheduling.  */
663   FILE *dump;
664 
665   /* Minimal cumulative weakness of speculative instruction's
666      dependencies, so that insn will be scheduled.  */
667   dw_t data_weakness_cutoff;
668 
669   /* Minimal usefulness of speculative instruction to be considered for
670      scheduling.  */
671   int control_weakness_cutoff;
672 
673   /* Flags from the enum SPEC_SCHED_FLAGS.  */
674   int flags;
675 };
676 typedef struct spec_info_def *spec_info_t;
677 
678 extern spec_info_t spec_info;
679 
680 extern struct haifa_sched_info *current_sched_info;
681 
682 /* Do register pressure sensitive insn scheduling if the flag is set
683    up.  */
684 extern enum sched_pressure_algorithm sched_pressure;
685 
686 /* Map regno -> its pressure class.  The map defined only when
687    SCHED_PRESSURE_P is true.  */
688 extern enum reg_class *sched_regno_pressure_class;
689 
690 /* Indexed by INSN_UID, the collection of all data associated with
691    a single instruction.  */
692 
693 struct _haifa_deps_insn_data
694 {
695   /* The number of incoming edges in the forward dependency graph.
696      As scheduling proceeds, counts are decreased.  An insn moves to
697      the ready queue when its counter reaches zero.  */
698   int dep_count;
699 
700   /* Nonzero if instruction has internal dependence
701      (e.g. add_dependence was invoked with (insn == elem)).  */
702   unsigned int has_internal_dep;
703 
704   /* NB: We can't place 'struct _deps_list' here instead of deps_list_t into
705      h_i_d because when h_i_d extends, addresses of the deps_list->first
706      change without updating deps_list->first->next->prev_nextp.  Thus
707      BACK_DEPS and RESOLVED_BACK_DEPS are allocated on the heap and FORW_DEPS
708      list is allocated on the obstack.  */
709 
710   /* A list of hard backward dependencies.  The insn is a consumer of all the
711      deps mentioned here.  */
712   deps_list_t hard_back_deps;
713 
714   /* A list of speculative (weak) dependencies.  The insn is a consumer of all
715      the deps mentioned here.  */
716   deps_list_t spec_back_deps;
717 
718   /* A list of insns which depend on the instruction.  Unlike 'back_deps',
719      it represents forward dependencies.  */
720   deps_list_t forw_deps;
721 
722   /* A list of scheduled producers of the instruction.  Links are being moved
723      from 'back_deps' to 'resolved_back_deps' while scheduling.  */
724   deps_list_t resolved_back_deps;
725 
726   /* A list of scheduled consumers of the instruction.  Links are being moved
727      from 'forw_deps' to 'resolved_forw_deps' while scheduling to fasten the
728      search in 'forw_deps'.  */
729   deps_list_t resolved_forw_deps;
730 
731   /* If the insn is conditional (either through COND_EXEC, or because
732      it is a conditional branch), this records the condition.  NULL
733      for insns that haven't been seen yet or don't have a condition;
734      const_true_rtx to mark an insn without a condition, or with a
735      condition that has been clobbered by a subsequent insn.  */
736   rtx cond;
737 
738   /* For a conditional insn, a list of insns that could set the condition
739      register.  Used when generating control dependencies.  */
740   rtx cond_deps;
741 
742   /* True if the condition in 'cond' should be reversed to get the actual
743      condition.  */
744   unsigned int reverse_cond : 1;
745 
746   /* Some insns (e.g. call) are not allowed to move across blocks.  */
747   unsigned int cant_move : 1;
748 };
749 
750 
751 /* Bits used for storing values of the fields in the following
752    structure.  */
753 #define INCREASE_BITS 8
754 
755 /* The structure describes how the corresponding insn increases the
756    register pressure for each pressure class.  */
757 struct reg_pressure_data
758 {
759   /* Pressure increase for given class because of clobber.  */
760   unsigned int clobber_increase : INCREASE_BITS;
761   /* Increase in register pressure for given class because of register
762      sets. */
763   unsigned int set_increase : INCREASE_BITS;
764   /* Pressure increase for given class because of unused register
765      set.  */
766   unsigned int unused_set_increase : INCREASE_BITS;
767   /* Pressure change: #sets - #deaths.  */
768   int change : INCREASE_BITS;
769 };
770 
771 /* The following structure describes usage of registers by insns.  */
772 struct reg_use_data
773 {
774   /* Regno used in the insn.  */
775   int regno;
776   /* Insn using the regno.  */
777   rtx insn;
778   /* Cyclic list of elements with the same regno.  */
779   struct reg_use_data *next_regno_use;
780   /* List of elements with the same insn.  */
781   struct reg_use_data *next_insn_use;
782 };
783 
784 /* The following structure describes used sets of registers by insns.
785    Registers are pseudos whose pressure class is not NO_REGS or hard
786    registers available for allocations.  */
787 struct reg_set_data
788 {
789   /* Regno used in the insn.  */
790   int regno;
791   /* Insn setting the regno.  */
792   rtx insn;
793   /* List of elements with the same insn.  */
794   struct reg_set_data *next_insn_set;
795 };
796 
797 struct _haifa_insn_data
798 {
799   /* We can't place 'struct _deps_list' into h_i_d instead of deps_list_t
800      because when h_i_d extends, addresses of the deps_list->first
801      change without updating deps_list->first->next->prev_nextp.  */
802 
803   /* Logical uid gives the original ordering of the insns.  */
804   int luid;
805 
806   /* A priority for each insn.  */
807   int priority;
808 
809   /* The minimum clock tick at which the insn becomes ready.  This is
810      used to note timing constraints for the insns in the pending list.  */
811   int tick;
812 
813   /* For insns that are scheduled at a fixed difference from another,
814      this records the tick in which they must be ready.  */
815   int exact_tick;
816 
817   /* INTER_TICK is used to adjust INSN_TICKs of instructions from the
818      subsequent blocks in a region.  */
819   int inter_tick;
820 
821   /* Used temporarily to estimate an INSN_TICK value for an insn given
822      current knowledge.  */
823   int tick_estimate;
824 
825   /* See comment on QUEUE_INDEX macro in haifa-sched.c.  */
826   int queue_index;
827 
828   short cost;
829 
830   /* '> 0' if priority is valid,
831      '== 0' if priority was not yet computed,
832      '< 0' if priority in invalid and should be recomputed.  */
833   signed char priority_status;
834 
835   /* Set if there's DEF-USE dependence between some speculatively
836      moved load insn and this one.  */
837   unsigned int fed_by_spec_load : 1;
838   unsigned int is_load_insn : 1;
839   /* Nonzero if this insn has negative-cost forward dependencies against
840      an already scheduled insn.  */
841   unsigned int feeds_backtrack_insn : 1;
842 
843   /* Nonzero if this insn is a shadow of another, scheduled after a fixed
844      delay.  We only emit shadows at the end of a cycle, with no other
845      real insns following them.  */
846   unsigned int shadow_p : 1;
847 
848   /* Used internally in unschedule_insns_until to mark insns that must have
849      their TODO_SPEC recomputed.  */
850   unsigned int must_recompute_spec : 1;
851 
852   /* What speculations are necessary to apply to schedule the instruction.  */
853   ds_t todo_spec;
854 
855   /* What speculations were already applied.  */
856   ds_t done_spec;
857 
858   /* What speculations are checked by this instruction.  */
859   ds_t check_spec;
860 
861   /* Recovery block for speculation checks.  */
862   basic_block recovery_block;
863 
864   /* Original pattern of the instruction.  */
865   rtx orig_pat;
866 
867   /* For insns with DEP_CONTROL dependencies, the predicated pattern if it
868      was ever successfully constructed.  */
869   rtx predicated_pat;
870 
871   /* The following array contains info how the insn increases register
872      pressure.  There is an element for each cover class of pseudos
873      referenced in insns.  */
874   struct reg_pressure_data *reg_pressure;
875   /* The following array contains maximal reg pressure between last
876      scheduled insn and given insn.  There is an element for each
877      pressure class of pseudos referenced in insns.  This info updated
878      after scheduling each insn for each insn between the two
879      mentioned insns.  */
880   int *max_reg_pressure;
881   /* The following list contains info about used pseudos and hard
882      registers available for allocation.  */
883   struct reg_use_data *reg_use_list;
884   /* The following list contains info about set pseudos and hard
885      registers available for allocation.  */
886   struct reg_set_data *reg_set_list;
887   /* Info about how scheduling the insn changes cost of register
888      pressure excess (between source and target).  */
889   int reg_pressure_excess_cost_change;
890   int model_index;
891 };
892 
893 typedef struct _haifa_insn_data haifa_insn_data_def;
894 typedef haifa_insn_data_def *haifa_insn_data_t;
895 
896 
897 extern vec<haifa_insn_data_def> h_i_d;
898 
899 #define HID(INSN) (&h_i_d[INSN_UID (INSN)])
900 
901 /* Accessor macros for h_i_d.  There are more in haifa-sched.c and
902    sched-rgn.c.  */
903 #define INSN_PRIORITY(INSN) (HID (INSN)->priority)
904 #define INSN_REG_PRESSURE(INSN) (HID (INSN)->reg_pressure)
905 #define INSN_MAX_REG_PRESSURE(INSN) (HID (INSN)->max_reg_pressure)
906 #define INSN_REG_USE_LIST(INSN) (HID (INSN)->reg_use_list)
907 #define INSN_REG_SET_LIST(INSN) (HID (INSN)->reg_set_list)
908 #define INSN_REG_PRESSURE_EXCESS_COST_CHANGE(INSN) \
909   (HID (INSN)->reg_pressure_excess_cost_change)
910 #define INSN_PRIORITY_STATUS(INSN) (HID (INSN)->priority_status)
911 #define INSN_MODEL_INDEX(INSN) (HID (INSN)->model_index)
912 
913 typedef struct _haifa_deps_insn_data haifa_deps_insn_data_def;
914 typedef haifa_deps_insn_data_def *haifa_deps_insn_data_t;
915 
916 
917 extern vec<haifa_deps_insn_data_def> h_d_i_d;
918 
919 #define HDID(INSN) (&h_d_i_d[INSN_LUID (INSN)])
920 #define INSN_DEP_COUNT(INSN)	(HDID (INSN)->dep_count)
921 #define HAS_INTERNAL_DEP(INSN)  (HDID (INSN)->has_internal_dep)
922 #define INSN_FORW_DEPS(INSN) (HDID (INSN)->forw_deps)
923 #define INSN_RESOLVED_BACK_DEPS(INSN) (HDID (INSN)->resolved_back_deps)
924 #define INSN_RESOLVED_FORW_DEPS(INSN) (HDID (INSN)->resolved_forw_deps)
925 #define INSN_HARD_BACK_DEPS(INSN) (HDID (INSN)->hard_back_deps)
926 #define INSN_SPEC_BACK_DEPS(INSN) (HDID (INSN)->spec_back_deps)
927 #define INSN_CACHED_COND(INSN)	(HDID (INSN)->cond)
928 #define INSN_REVERSE_COND(INSN) (HDID (INSN)->reverse_cond)
929 #define INSN_COND_DEPS(INSN)	(HDID (INSN)->cond_deps)
930 #define CANT_MOVE(INSN)	(HDID (INSN)->cant_move)
931 #define CANT_MOVE_BY_LUID(LUID)	(h_d_i_d[LUID].cant_move)
932 
933 
934 #define INSN_PRIORITY(INSN)	(HID (INSN)->priority)
935 #define INSN_PRIORITY_STATUS(INSN) (HID (INSN)->priority_status)
936 #define INSN_PRIORITY_KNOWN(INSN) (INSN_PRIORITY_STATUS (INSN) > 0)
937 #define TODO_SPEC(INSN) (HID (INSN)->todo_spec)
938 #define DONE_SPEC(INSN) (HID (INSN)->done_spec)
939 #define CHECK_SPEC(INSN) (HID (INSN)->check_spec)
940 #define RECOVERY_BLOCK(INSN) (HID (INSN)->recovery_block)
941 #define ORIG_PAT(INSN) (HID (INSN)->orig_pat)
942 #define PREDICATED_PAT(INSN) (HID (INSN)->predicated_pat)
943 
944 /* INSN is either a simple or a branchy speculation check.  */
945 #define IS_SPECULATION_CHECK_P(INSN) \
946   (sel_sched_p () ? sel_insn_is_speculation_check (INSN) : RECOVERY_BLOCK (INSN) != NULL)
947 
948 /* INSN is a speculation check that will simply reexecute the speculatively
949    scheduled instruction if the speculation fails.  */
950 #define IS_SPECULATION_SIMPLE_CHECK_P(INSN) \
951   (RECOVERY_BLOCK (INSN) == EXIT_BLOCK_PTR_FOR_FN (cfun))
952 
953 /* INSN is a speculation check that will branch to RECOVERY_BLOCK if the
954    speculation fails.  Insns in that block will reexecute the speculatively
955    scheduled code and then will return immediately after INSN thus preserving
956    semantics of the program.  */
957 #define IS_SPECULATION_BRANCHY_CHECK_P(INSN) \
958   (RECOVERY_BLOCK (INSN) != NULL             \
959    && RECOVERY_BLOCK (INSN) != EXIT_BLOCK_PTR_FOR_FN (cfun))
960 
961 
962 /* Dep status (aka ds_t) of the link encapsulates all information for a given
963    dependency, including everything that is needed for speculative scheduling.
964 
965    The lay-out of a ds_t is as follows:
966 
967    1. Integers corresponding to the probability of the dependence to *not*
968       exist.  This is the probability that overcoming this dependence will
969       not be followed by execution of the recovery code.  Note that however
970       high this probability is, the recovery code should still always be
971       generated to preserve semantics of the program.
972 
973       The probability values can be set or retrieved using the functions
974       the set_dep_weak() and get_dep_weak() in sched-deps.c.  The values
975       are always in the range [0, MAX_DEP_WEAK].
976 
977 	BEGIN_DATA	: BITS_PER_DEP_WEAK
978 	BE_IN_DATA	: BITS_PER_DEP_WEAK
979 	BEGIN_CONTROL	: BITS_PER_DEP_WEAK
980 	BE_IN_CONTROL	: BITS_PER_DEP_WEAK
981 
982       The basic type of DS_T is a host int.  For a 32-bits int, the values
983       will each take 6 bits.
984 
985    2. The type of dependence.  This supercedes the old-style REG_NOTE_KIND
986       values.  TODO: Use this field instead of DEP_TYPE, or make DEP_TYPE
987       extract the dependence type from here.
988 
989 	dep_type	:  4 => DEP_{TRUE|OUTPUT|ANTI|CONTROL}
990 
991    3. Various flags:
992 
993 	HARD_DEP	:  1 =>	Set if an instruction has a non-speculative
994 				dependence.  This is an instruction property
995 				so this bit can only appear in the TODO_SPEC
996 				field of an instruction.
997 	DEP_POSTPONED	:  1 =>	Like HARD_DEP, but the hard dependence may
998 				still be broken by adjusting the instruction.
999 	DEP_CANCELLED	:  1 =>	Set if a dependency has been broken using
1000 				some form of speculation.
1001 	RESERVED	:  1 => Reserved for use in the delay slot scheduler.
1002 
1003    See also: check_dep_status () in sched-deps.c .  */
1004 
1005 /* The number of bits per weakness probability.  There are 4 weakness types
1006    and we need 8 bits for other data in a DS_T.  */
1007 #define BITS_PER_DEP_WEAK ((BITS_PER_DEP_STATUS - 8) / 4)
1008 
1009 /* Mask of speculative weakness in dep_status.  */
1010 #define DEP_WEAK_MASK ((1 << BITS_PER_DEP_WEAK) - 1)
1011 
1012 /* This constant means that dependence is fake with 99.999...% probability.
1013    This is the maximum value, that can appear in dep_status.
1014    Note, that we don't want MAX_DEP_WEAK to be the same as DEP_WEAK_MASK for
1015    debugging reasons.  Though, it can be set to DEP_WEAK_MASK, and, when
1016    done so, we'll get fast (mul for)/(div by) NO_DEP_WEAK.  */
1017 #define MAX_DEP_WEAK (DEP_WEAK_MASK - 1)
1018 
1019 /* This constant means that dependence is 99.999...% real and it is a really
1020    bad idea to overcome it (though this can be done, preserving program
1021    semantics).  */
1022 #define MIN_DEP_WEAK 1
1023 
1024 /* This constant represents 100% probability.
1025    E.g. it is used to represent weakness of dependence, that doesn't exist.
1026    This value never appears in a ds_t, it is only used for computing the
1027    weakness of a dependence.  */
1028 #define NO_DEP_WEAK (MAX_DEP_WEAK + MIN_DEP_WEAK)
1029 
1030 /* Default weakness of speculative dependence.  Used when we can't say
1031    neither bad nor good about the dependence.  */
1032 #define UNCERTAIN_DEP_WEAK (MAX_DEP_WEAK - MAX_DEP_WEAK / 4)
1033 
1034 /* Offset for speculative weaknesses in dep_status.  */
1035 enum SPEC_TYPES_OFFSETS {
1036   BEGIN_DATA_BITS_OFFSET = 0,
1037   BE_IN_DATA_BITS_OFFSET = BEGIN_DATA_BITS_OFFSET + BITS_PER_DEP_WEAK,
1038   BEGIN_CONTROL_BITS_OFFSET = BE_IN_DATA_BITS_OFFSET + BITS_PER_DEP_WEAK,
1039   BE_IN_CONTROL_BITS_OFFSET = BEGIN_CONTROL_BITS_OFFSET + BITS_PER_DEP_WEAK
1040 };
1041 
1042 /* The following defines provide numerous constants used to distinguish
1043    between different types of speculative dependencies.  They are also
1044    used as masks to clear/preserve the bits corresponding to the type
1045    of dependency weakness.  */
1046 
1047 /* Dependence can be overcome with generation of new data speculative
1048    instruction.  */
1049 #define BEGIN_DATA (((ds_t) DEP_WEAK_MASK) << BEGIN_DATA_BITS_OFFSET)
1050 
1051 /* This dependence is to the instruction in the recovery block, that was
1052    formed to recover after data-speculation failure.
1053    Thus, this dependence can overcome with generating of the copy of
1054    this instruction in the recovery block.  */
1055 #define BE_IN_DATA (((ds_t) DEP_WEAK_MASK) << BE_IN_DATA_BITS_OFFSET)
1056 
1057 /* Dependence can be overcome with generation of new control speculative
1058    instruction.  */
1059 #define BEGIN_CONTROL (((ds_t) DEP_WEAK_MASK) << BEGIN_CONTROL_BITS_OFFSET)
1060 
1061 /* This dependence is to the instruction in the recovery block, that was
1062    formed to recover after control-speculation failure.
1063    Thus, this dependence can be overcome with generating of the copy of
1064    this instruction in the recovery block.  */
1065 #define BE_IN_CONTROL (((ds_t) DEP_WEAK_MASK) << BE_IN_CONTROL_BITS_OFFSET)
1066 
1067 /* A few convenient combinations.  */
1068 #define BEGIN_SPEC (BEGIN_DATA | BEGIN_CONTROL)
1069 #define DATA_SPEC (BEGIN_DATA | BE_IN_DATA)
1070 #define CONTROL_SPEC (BEGIN_CONTROL | BE_IN_CONTROL)
1071 #define SPECULATIVE (DATA_SPEC | CONTROL_SPEC)
1072 #define BE_IN_SPEC (BE_IN_DATA | BE_IN_CONTROL)
1073 
1074 /* Constants, that are helpful in iterating through dep_status.  */
1075 #define FIRST_SPEC_TYPE BEGIN_DATA
1076 #define LAST_SPEC_TYPE BE_IN_CONTROL
1077 #define SPEC_TYPE_SHIFT BITS_PER_DEP_WEAK
1078 
1079 /* Dependence on instruction can be of multiple types
1080    (e.g. true and output). This fields enhance REG_NOTE_KIND information
1081    of the dependence.  */
1082 #define DEP_TRUE (((ds_t) 1) << (BE_IN_CONTROL_BITS_OFFSET + BITS_PER_DEP_WEAK))
1083 #define DEP_OUTPUT (DEP_TRUE << 1)
1084 #define DEP_ANTI (DEP_OUTPUT << 1)
1085 #define DEP_CONTROL (DEP_ANTI << 1)
1086 
1087 #define DEP_TYPES (DEP_TRUE | DEP_OUTPUT | DEP_ANTI | DEP_CONTROL)
1088 
1089 /* Instruction has non-speculative dependence.  This bit represents the
1090    property of an instruction - not the one of a dependence.
1091    Therefore, it can appear only in the TODO_SPEC field of an instruction.  */
1092 #define HARD_DEP (DEP_CONTROL << 1)
1093 
1094 /* Like HARD_DEP, but dependencies can perhaps be broken by modifying
1095    the instructions.  This is used for example to change:
1096 
1097    rn++		=>	rm=[rn + 4]
1098    rm=[rn]		rn++
1099 
1100    For instructions that have this bit set, one of the dependencies of
1101    the instructions will have a non-NULL REPLACE field in its DEP_T.
1102    Just like HARD_DEP, this bit is only ever set in TODO_SPEC.  */
1103 #define DEP_POSTPONED (HARD_DEP << 1)
1104 
1105 /* Set if a dependency is cancelled via speculation.  */
1106 #define DEP_CANCELLED (DEP_POSTPONED << 1)
1107 
1108 
1109 /* This represents the results of calling sched-deps.c functions,
1110    which modify dependencies.  */
1111 enum DEPS_ADJUST_RESULT {
1112   /* No dependence needed (e.g. producer == consumer).  */
1113   DEP_NODEP,
1114   /* Dependence is already present and wasn't modified.  */
1115   DEP_PRESENT,
1116   /* Existing dependence was modified to include additional information.  */
1117   DEP_CHANGED,
1118   /* New dependence has been created.  */
1119   DEP_CREATED
1120 };
1121 
1122 /* Represents the bits that can be set in the flags field of the
1123    sched_info structure.  */
1124 enum SCHED_FLAGS {
1125   /* If set, generate links between instruction as DEPS_LIST.
1126      Otherwise, generate usual INSN_LIST links.  */
1127   USE_DEPS_LIST = 1,
1128   /* Perform data or control (or both) speculation.
1129      Results in generation of data and control speculative dependencies.
1130      Requires USE_DEPS_LIST set.  */
1131   DO_SPECULATION = USE_DEPS_LIST << 1,
1132   DO_BACKTRACKING = DO_SPECULATION << 1,
1133   DO_PREDICATION = DO_BACKTRACKING << 1,
1134   DONT_BREAK_DEPENDENCIES = DO_PREDICATION << 1,
1135   SCHED_RGN = DONT_BREAK_DEPENDENCIES << 1,
1136   SCHED_EBB = SCHED_RGN << 1,
1137   /* Scheduler can possibly create new basic blocks.  Used for assertions.  */
1138   NEW_BBS = SCHED_EBB << 1,
1139   SEL_SCHED = NEW_BBS << 1
1140 };
1141 
1142 enum SPEC_SCHED_FLAGS {
1143   COUNT_SPEC_IN_CRITICAL_PATH = 1,
1144   PREFER_NON_DATA_SPEC = COUNT_SPEC_IN_CRITICAL_PATH << 1,
1145   PREFER_NON_CONTROL_SPEC = PREFER_NON_DATA_SPEC << 1,
1146   SEL_SCHED_SPEC_DONT_CHECK_CONTROL = PREFER_NON_CONTROL_SPEC << 1
1147 };
1148 
1149 #define NOTE_NOT_BB_P(NOTE) (NOTE_P (NOTE) && (NOTE_KIND (NOTE)	\
1150 					       != NOTE_INSN_BASIC_BLOCK))
1151 
1152 extern FILE *sched_dump;
1153 extern int sched_verbose;
1154 
1155 extern spec_info_t spec_info;
1156 extern bool haifa_recovery_bb_ever_added_p;
1157 
1158 /* Exception Free Loads:
1159 
1160    We define five classes of speculative loads: IFREE, IRISKY,
1161    PFREE, PRISKY, and MFREE.
1162 
1163    IFREE loads are loads that are proved to be exception-free, just
1164    by examining the load insn.  Examples for such loads are loads
1165    from TOC and loads of global data.
1166 
1167    IRISKY loads are loads that are proved to be exception-risky,
1168    just by examining the load insn.  Examples for such loads are
1169    volatile loads and loads from shared memory.
1170 
1171    PFREE loads are loads for which we can prove, by examining other
1172    insns, that they are exception-free.  Currently, this class consists
1173    of loads for which we are able to find a "similar load", either in
1174    the target block, or, if only one split-block exists, in that split
1175    block.  Load2 is similar to load1 if both have same single base
1176    register.  We identify only part of the similar loads, by finding
1177    an insn upon which both load1 and load2 have a DEF-USE dependence.
1178 
1179    PRISKY loads are loads for which we can prove, by examining other
1180    insns, that they are exception-risky.  Currently we have two proofs for
1181    such loads.  The first proof detects loads that are probably guarded by a
1182    test on the memory address.  This proof is based on the
1183    backward and forward data dependence information for the region.
1184    Let load-insn be the examined load.
1185    Load-insn is PRISKY iff ALL the following hold:
1186 
1187    - insn1 is not in the same block as load-insn
1188    - there is a DEF-USE dependence chain (insn1, ..., load-insn)
1189    - test-insn is either a compare or a branch, not in the same block
1190      as load-insn
1191    - load-insn is reachable from test-insn
1192    - there is a DEF-USE dependence chain (insn1, ..., test-insn)
1193 
1194    This proof might fail when the compare and the load are fed
1195    by an insn not in the region.  To solve this, we will add to this
1196    group all loads that have no input DEF-USE dependence.
1197 
1198    The second proof detects loads that are directly or indirectly
1199    fed by a speculative load.  This proof is affected by the
1200    scheduling process.  We will use the flag  fed_by_spec_load.
1201    Initially, all insns have this flag reset.  After a speculative
1202    motion of an insn, if insn is either a load, or marked as
1203    fed_by_spec_load, we will also mark as fed_by_spec_load every
1204    insn1 for which a DEF-USE dependence (insn, insn1) exists.  A
1205    load which is fed_by_spec_load is also PRISKY.
1206 
1207    MFREE (maybe-free) loads are all the remaining loads. They may be
1208    exception-free, but we cannot prove it.
1209 
1210    Now, all loads in IFREE and PFREE classes are considered
1211    exception-free, while all loads in IRISKY and PRISKY classes are
1212    considered exception-risky.  As for loads in the MFREE class,
1213    these are considered either exception-free or exception-risky,
1214    depending on whether we are pessimistic or optimistic.  We have
1215    to take the pessimistic approach to assure the safety of
1216    speculative scheduling, but we can take the optimistic approach
1217    by invoking the -fsched_spec_load_dangerous option.  */
1218 
1219 enum INSN_TRAP_CLASS
1220 {
1221   TRAP_FREE = 0, IFREE = 1, PFREE_CANDIDATE = 2,
1222   PRISKY_CANDIDATE = 3, IRISKY = 4, TRAP_RISKY = 5
1223 };
1224 
1225 #define WORST_CLASS(class1, class2) \
1226 ((class1 > class2) ? class1 : class2)
1227 
1228 #ifndef __GNUC__
1229 #define __inline
1230 #endif
1231 
1232 #ifndef HAIFA_INLINE
1233 #define HAIFA_INLINE __inline
1234 #endif
1235 
1236 struct sched_deps_info_def
1237 {
1238   /* Called when computing dependencies for a JUMP_INSN.  This function
1239      should store the set of registers that must be considered as set by
1240      the jump in the regset.  */
1241   void (*compute_jump_reg_dependencies) (rtx, regset);
1242 
1243   /* Start analyzing insn.  */
1244   void (*start_insn) (rtx);
1245 
1246   /* Finish analyzing insn.  */
1247   void (*finish_insn) (void);
1248 
1249   /* Start analyzing insn LHS (Left Hand Side).  */
1250   void (*start_lhs) (rtx);
1251 
1252   /* Finish analyzing insn LHS.  */
1253   void (*finish_lhs) (void);
1254 
1255   /* Start analyzing insn RHS (Right Hand Side).  */
1256   void (*start_rhs) (rtx);
1257 
1258   /* Finish analyzing insn RHS.  */
1259   void (*finish_rhs) (void);
1260 
1261   /* Note set of the register.  */
1262   void (*note_reg_set) (int);
1263 
1264   /* Note clobber of the register.  */
1265   void (*note_reg_clobber) (int);
1266 
1267   /* Note use of the register.  */
1268   void (*note_reg_use) (int);
1269 
1270   /* Note memory dependence of type DS between MEM1 and MEM2 (which is
1271      in the INSN2).  */
1272   void (*note_mem_dep) (rtx mem1, rtx mem2, rtx insn2, ds_t ds);
1273 
1274   /* Note a dependence of type DS from the INSN.  */
1275   void (*note_dep) (rtx insn, ds_t ds);
1276 
1277   /* Nonzero if we should use cselib for better alias analysis.  This
1278      must be 0 if the dependency information is used after sched_analyze
1279      has completed, e.g. if we're using it to initialize state for successor
1280      blocks in region scheduling.  */
1281   unsigned int use_cselib : 1;
1282 
1283   /* If set, generate links between instruction as DEPS_LIST.
1284      Otherwise, generate usual INSN_LIST links.  */
1285   unsigned int use_deps_list : 1;
1286 
1287   /* Generate data and control speculative dependencies.
1288      Requires USE_DEPS_LIST set.  */
1289   unsigned int generate_spec_deps : 1;
1290 };
1291 
1292 extern struct sched_deps_info_def *sched_deps_info;
1293 
1294 
1295 /* Functions in sched-deps.c.  */
1296 extern rtx sched_get_reverse_condition_uncached (const_rtx);
1297 extern bool sched_insns_conditions_mutex_p (const_rtx, const_rtx);
1298 extern bool sched_insn_is_legitimate_for_speculation_p (const_rtx, ds_t);
1299 extern void add_dependence (rtx, rtx, enum reg_note);
1300 extern void sched_analyze (struct deps_desc *, rtx, rtx);
1301 extern void init_deps (struct deps_desc *, bool);
1302 extern void init_deps_reg_last (struct deps_desc *);
1303 extern void free_deps (struct deps_desc *);
1304 extern void init_deps_global (void);
1305 extern void finish_deps_global (void);
1306 extern void deps_analyze_insn (struct deps_desc *, rtx);
1307 extern void remove_from_deps (struct deps_desc *, rtx);
1308 extern void init_insn_reg_pressure_info (rtx);
1309 
1310 extern dw_t get_dep_weak (ds_t, ds_t);
1311 extern ds_t set_dep_weak (ds_t, ds_t, dw_t);
1312 extern dw_t estimate_dep_weak (rtx, rtx);
1313 extern ds_t ds_merge (ds_t, ds_t);
1314 extern ds_t ds_full_merge (ds_t, ds_t, rtx, rtx);
1315 extern ds_t ds_max_merge (ds_t, ds_t);
1316 extern dw_t ds_weak (ds_t);
1317 extern ds_t ds_get_speculation_types (ds_t);
1318 extern ds_t ds_get_max_dep_weak (ds_t);
1319 
1320 extern void sched_deps_init (bool);
1321 extern void sched_deps_finish (void);
1322 
1323 extern void haifa_note_reg_set (int);
1324 extern void haifa_note_reg_clobber (int);
1325 extern void haifa_note_reg_use (int);
1326 
1327 extern void maybe_extend_reg_info_p (void);
1328 
1329 extern void deps_start_bb (struct deps_desc *, rtx);
1330 extern enum reg_note ds_to_dt (ds_t);
1331 
1332 extern bool deps_pools_are_empty_p (void);
1333 extern void sched_free_deps (rtx, rtx, bool);
1334 extern void extend_dependency_caches (int, bool);
1335 
1336 extern void debug_ds (ds_t);
1337 
1338 
1339 /* Functions in haifa-sched.c.  */
1340 extern void initialize_live_range_shrinkage (void);
1341 extern void finish_live_range_shrinkage (void);
1342 extern void sched_init_region_reg_pressure_info (void);
1343 extern void free_global_sched_pressure_data (void);
1344 extern int haifa_classify_insn (const_rtx);
1345 extern void get_ebb_head_tail (basic_block, basic_block, rtx *, rtx *);
1346 extern int no_real_insns_p (const_rtx, const_rtx);
1347 
1348 extern int insn_cost (rtx);
1349 extern int dep_cost_1 (dep_t, dw_t);
1350 extern int dep_cost (dep_t);
1351 extern int set_priorities (rtx, rtx);
1352 
1353 extern void sched_setup_bb_reg_pressure_info (basic_block, rtx);
1354 extern bool schedule_block (basic_block *, state_t);
1355 
1356 extern int cycle_issued_insns;
1357 extern int issue_rate;
1358 extern int dfa_lookahead;
1359 
1360 extern void ready_sort (struct ready_list *);
1361 extern rtx ready_element (struct ready_list *, int);
1362 extern rtx *ready_lastpos (struct ready_list *);
1363 
1364 extern int try_ready (rtx);
1365 extern void sched_extend_ready_list (int);
1366 extern void sched_finish_ready_list (void);
1367 extern void sched_change_pattern (rtx, rtx);
1368 extern int sched_speculate_insn (rtx, ds_t, rtx *);
1369 extern void unlink_bb_notes (basic_block, basic_block);
1370 extern void add_block (basic_block, basic_block);
1371 extern rtx bb_note (basic_block);
1372 extern void concat_note_lists (rtx, rtx *);
1373 extern rtx sched_emit_insn (rtx);
1374 extern rtx get_ready_element (int);
1375 extern int number_in_ready (void);
1376 
1377 /* Types and functions in sched-ebb.c.  */
1378 
1379 extern basic_block schedule_ebb (rtx, rtx, bool);
1380 extern void schedule_ebbs_init (void);
1381 extern void schedule_ebbs_finish (void);
1382 
1383 /* Types and functions in sched-rgn.c.  */
1384 
1385 /* A region is the main entity for interblock scheduling: insns
1386    are allowed to move between blocks in the same region, along
1387    control flow graph edges, in the 'up' direction.  */
1388 struct region
1389 {
1390   /* Number of extended basic blocks in region.  */
1391   int rgn_nr_blocks;
1392   /* cblocks in the region (actually index in rgn_bb_table).  */
1393   int rgn_blocks;
1394   /* Dependencies for this region are already computed.  Basically, indicates,
1395      that this is a recovery block.  */
1396   unsigned int dont_calc_deps : 1;
1397   /* This region has at least one non-trivial ebb.  */
1398   unsigned int has_real_ebb : 1;
1399 };
1400 
1401 extern int nr_regions;
1402 extern region *rgn_table;
1403 extern int *rgn_bb_table;
1404 extern int *block_to_bb;
1405 extern int *containing_rgn;
1406 
1407 /* Often used short-hand in the scheduler.  The rest of the compiler uses
1408    BLOCK_FOR_INSN(INSN) and an indirect reference to get the basic block
1409    number ("index").  For historical reasons, the scheduler does not.  */
1410 #define BLOCK_NUM(INSN)	      (BLOCK_FOR_INSN (INSN)->index + 0)
1411 
1412 #define RGN_NR_BLOCKS(rgn) (rgn_table[rgn].rgn_nr_blocks)
1413 #define RGN_BLOCKS(rgn) (rgn_table[rgn].rgn_blocks)
1414 #define RGN_DONT_CALC_DEPS(rgn) (rgn_table[rgn].dont_calc_deps)
1415 #define RGN_HAS_REAL_EBB(rgn) (rgn_table[rgn].has_real_ebb)
1416 #define BLOCK_TO_BB(block) (block_to_bb[block])
1417 #define CONTAINING_RGN(block) (containing_rgn[block])
1418 
1419 /* The mapping from ebb to block.  */
1420 extern int *ebb_head;
1421 #define BB_TO_BLOCK(ebb) (rgn_bb_table[ebb_head[ebb]])
1422 #define EBB_FIRST_BB(ebb) BASIC_BLOCK_FOR_FN (cfun, BB_TO_BLOCK (ebb))
1423 #define EBB_LAST_BB(ebb) \
1424   BASIC_BLOCK_FOR_FN (cfun, rgn_bb_table[ebb_head[ebb + 1] - 1])
1425 #define INSN_BB(INSN) (BLOCK_TO_BB (BLOCK_NUM (INSN)))
1426 
1427 extern int current_nr_blocks;
1428 extern int current_blocks;
1429 extern int target_bb;
1430 extern bool sched_no_dce;
1431 
1432 extern void set_modulo_params (int, int, int, int);
1433 extern void record_delay_slot_pair (rtx, rtx, int, int);
1434 extern rtx real_insn_for_shadow (rtx);
1435 extern void discard_delay_pairs_above (int);
1436 extern void free_delay_pairs (void);
1437 extern void add_delay_dependencies (rtx);
1438 extern bool sched_is_disabled_for_current_region_p (void);
1439 extern void sched_rgn_init (bool);
1440 extern void sched_rgn_finish (void);
1441 extern void rgn_setup_region (int);
1442 extern void sched_rgn_compute_dependencies (int);
1443 extern void sched_rgn_local_init (int);
1444 extern void sched_rgn_local_finish (void);
1445 extern void sched_rgn_local_free (void);
1446 extern void extend_regions (void);
1447 extern void rgn_make_new_region_out_of_new_block (basic_block);
1448 
1449 extern void compute_priorities (void);
1450 extern void increase_insn_priority (rtx, int);
1451 extern void debug_rgn_dependencies (int);
1452 extern void debug_dependencies (rtx, rtx);
1453 extern void free_rgn_deps (void);
1454 extern int contributes_to_priority (rtx, rtx);
1455 extern void extend_rgns (int *, int *, sbitmap, int *);
1456 extern void deps_join (struct deps_desc *, struct deps_desc *);
1457 
1458 extern void rgn_setup_common_sched_info (void);
1459 extern void rgn_setup_sched_infos (void);
1460 
1461 extern void debug_regions (void);
1462 extern void debug_region (int);
1463 extern void dump_region_dot (FILE *, int);
1464 extern void dump_region_dot_file (const char *, int);
1465 
1466 extern void haifa_sched_init (void);
1467 extern void haifa_sched_finish (void);
1468 
1469 extern void find_modifiable_mems (rtx, rtx);
1470 
1471 /* sched-deps.c interface to walk, add, search, update, resolve, delete
1472    and debug instruction dependencies.  */
1473 
1474 /* Constants defining dependences lists.  */
1475 
1476 /* No list.  */
1477 #define SD_LIST_NONE (0)
1478 
1479 /* hard_back_deps.  */
1480 #define SD_LIST_HARD_BACK (1)
1481 
1482 /* spec_back_deps.  */
1483 #define SD_LIST_SPEC_BACK (2)
1484 
1485 /* forw_deps.  */
1486 #define SD_LIST_FORW (4)
1487 
1488 /* resolved_back_deps.  */
1489 #define SD_LIST_RES_BACK (8)
1490 
1491 /* resolved_forw_deps.  */
1492 #define SD_LIST_RES_FORW (16)
1493 
1494 #define SD_LIST_BACK (SD_LIST_HARD_BACK | SD_LIST_SPEC_BACK)
1495 
1496 /* A type to hold above flags.  */
1497 typedef int sd_list_types_def;
1498 
1499 extern void sd_next_list (const_rtx, sd_list_types_def *, deps_list_t *, bool *);
1500 
1501 /* Iterator to walk through, resolve and delete dependencies.  */
1502 struct _sd_iterator
1503 {
1504   /* What lists to walk.  Can be any combination of SD_LIST_* flags.  */
1505   sd_list_types_def types;
1506 
1507   /* Instruction dependencies lists of which will be walked.  */
1508   rtx insn;
1509 
1510   /* Pointer to the next field of the previous element.  This is not
1511      simply a pointer to the next element to allow easy deletion from the
1512      list.  When a dep is being removed from the list the iterator
1513      will automatically advance because the value in *linkp will start
1514      referring to the next element.  */
1515   dep_link_t *linkp;
1516 
1517   /* True if the current list is a resolved one.  */
1518   bool resolved_p;
1519 };
1520 
1521 typedef struct _sd_iterator sd_iterator_def;
1522 
1523 /* ??? We can move some definitions that are used in below inline functions
1524    out of sched-int.h to sched-deps.c provided that the below functions will
1525    become global externals.
1526    These definitions include:
1527    * struct _deps_list: opaque pointer is needed at global scope.
1528    * struct _dep_link: opaque pointer is needed at scope of sd_iterator_def.
1529    * struct _dep_node: opaque pointer is needed at scope of
1530    struct _deps_link.  */
1531 
1532 /* Return initialized iterator.  */
1533 static inline sd_iterator_def
sd_iterator_start(rtx insn,sd_list_types_def types)1534 sd_iterator_start (rtx insn, sd_list_types_def types)
1535 {
1536   /* Some dep_link a pointer to which will return NULL.  */
1537   static dep_link_t null_link = NULL;
1538 
1539   sd_iterator_def i;
1540 
1541   i.types = types;
1542   i.insn = insn;
1543   i.linkp = &null_link;
1544 
1545   /* Avoid 'uninitialized warning'.  */
1546   i.resolved_p = false;
1547 
1548   return i;
1549 }
1550 
1551 /* Return the current element.  */
1552 static inline bool
sd_iterator_cond(sd_iterator_def * it_ptr,dep_t * dep_ptr)1553 sd_iterator_cond (sd_iterator_def *it_ptr, dep_t *dep_ptr)
1554 {
1555   dep_link_t link = *it_ptr->linkp;
1556 
1557   if (link != NULL)
1558     {
1559       *dep_ptr = DEP_LINK_DEP (link);
1560       return true;
1561     }
1562   else
1563     {
1564       sd_list_types_def types = it_ptr->types;
1565 
1566       if (types != SD_LIST_NONE)
1567 	/* Switch to next list.  */
1568 	{
1569 	  deps_list_t list;
1570 
1571 	  sd_next_list (it_ptr->insn,
1572 			&it_ptr->types, &list, &it_ptr->resolved_p);
1573 
1574 	  it_ptr->linkp = &DEPS_LIST_FIRST (list);
1575 
1576 	  if (list)
1577 	    return sd_iterator_cond (it_ptr, dep_ptr);
1578 	}
1579 
1580       *dep_ptr = NULL;
1581       return false;
1582     }
1583 }
1584 
1585 /* Advance iterator.  */
1586 static inline void
sd_iterator_next(sd_iterator_def * it_ptr)1587 sd_iterator_next (sd_iterator_def *it_ptr)
1588 {
1589   it_ptr->linkp = &DEP_LINK_NEXT (*it_ptr->linkp);
1590 }
1591 
1592 /* A cycle wrapper.  */
1593 #define FOR_EACH_DEP(INSN, LIST_TYPES, ITER, DEP)		\
1594   for ((ITER) = sd_iterator_start ((INSN), (LIST_TYPES));	\
1595        sd_iterator_cond (&(ITER), &(DEP));			\
1596        sd_iterator_next (&(ITER)))
1597 
1598 #define IS_DISPATCH_ON 1
1599 #define IS_CMP 2
1600 #define DISPATCH_VIOLATION 3
1601 #define FITS_DISPATCH_WINDOW 4
1602 #define DISPATCH_INIT 5
1603 #define ADD_TO_DISPATCH_WINDOW 6
1604 
1605 extern int sd_lists_size (const_rtx, sd_list_types_def);
1606 extern bool sd_lists_empty_p (const_rtx, sd_list_types_def);
1607 extern void sd_init_insn (rtx);
1608 extern void sd_finish_insn (rtx);
1609 extern dep_t sd_find_dep_between (rtx, rtx, bool);
1610 extern void sd_add_dep (dep_t, bool);
1611 extern enum DEPS_ADJUST_RESULT sd_add_or_update_dep (dep_t, bool);
1612 extern void sd_resolve_dep (sd_iterator_def);
1613 extern void sd_unresolve_dep (sd_iterator_def);
1614 extern void sd_copy_back_deps (rtx, rtx, bool);
1615 extern void sd_delete_dep (sd_iterator_def);
1616 extern void sd_debug_lists (rtx, sd_list_types_def);
1617 
1618 #endif /* INSN_SCHEDULING */
1619 
1620 #endif /* GCC_SCHED_INT_H */
1621 
1622