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[official-gcc.git] / gcc / cfgloop.h
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1 /* Natural loop functions
2 Copyright (C) 1987-2017 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
9 version.
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 for more details.
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
20 #ifndef GCC_CFGLOOP_H
21 #define GCC_CFGLOOP_H
23 #include "cfgloopmanip.h"
25 /* Structure to hold decision about unrolling/peeling. */
26 enum lpt_dec
28 LPT_NONE,
29 LPT_UNROLL_CONSTANT,
30 LPT_UNROLL_RUNTIME,
31 LPT_UNROLL_STUPID
34 struct GTY (()) lpt_decision {
35 enum lpt_dec decision;
36 unsigned times;
39 /* The type of extend applied to an IV. */
40 enum iv_extend_code
42 IV_SIGN_EXTEND,
43 IV_ZERO_EXTEND,
44 IV_UNKNOWN_EXTEND
47 /* The structure describing a bound on number of iterations of a loop. */
49 struct GTY ((chain_next ("%h.next"))) nb_iter_bound {
50 /* The statement STMT is executed at most ... */
51 gimple *stmt;
53 /* ... BOUND + 1 times (BOUND must be an unsigned constant).
54 The + 1 is added for the following reasons:
56 a) 0 would otherwise be unused, while we would need to care more about
57 overflows (as MAX + 1 is sometimes produced as the estimate on number
58 of executions of STMT).
59 b) it is consistent with the result of number_of_iterations_exit. */
60 widest_int bound;
62 /* True if the statement will cause the loop to be leaved the (at most)
63 BOUND + 1-st time it is executed, that is, all the statements after it
64 are executed at most BOUND times. */
65 bool is_exit;
67 /* The next bound in the list. */
68 struct nb_iter_bound *next;
71 /* Description of the loop exit. */
73 struct GTY ((for_user)) loop_exit {
74 /* The exit edge. */
75 edge e;
77 /* Previous and next exit in the list of the exits of the loop. */
78 struct loop_exit *prev;
79 struct loop_exit *next;
81 /* Next element in the list of loops from that E exits. */
82 struct loop_exit *next_e;
85 struct loop_exit_hasher : ggc_ptr_hash<loop_exit>
87 typedef edge compare_type;
89 static hashval_t hash (loop_exit *);
90 static bool equal (loop_exit *, edge);
91 static void remove (loop_exit *);
94 typedef struct loop *loop_p;
96 /* An integer estimation of the number of iterations. Estimate_state
97 describes what is the state of the estimation. */
98 enum loop_estimation
100 /* Estimate was not computed yet. */
101 EST_NOT_COMPUTED,
102 /* Estimate is ready. */
103 EST_AVAILABLE,
104 EST_LAST
107 /* The structure describing non-overflow control induction variable for
108 loop's exit edge. */
109 struct GTY ((chain_next ("%h.next"))) control_iv {
110 tree base;
111 tree step;
112 struct control_iv *next;
115 /* Structure to hold information for each natural loop. */
116 struct GTY ((chain_next ("%h.next"))) loop {
117 /* Index into loops array. Note indices will never be reused after loop
118 is destroyed. */
119 int num;
121 /* Number of loop insns. */
122 unsigned ninsns;
124 /* Basic block of loop header. */
125 basic_block header;
127 /* Basic block of loop latch. */
128 basic_block latch;
130 /* For loop unrolling/peeling decision. */
131 struct lpt_decision lpt_decision;
133 /* Average number of executed insns per iteration. */
134 unsigned av_ninsns;
136 /* Number of blocks contained within the loop. */
137 unsigned num_nodes;
139 /* Superloops of the loop, starting with the outermost loop. */
140 vec<loop_p, va_gc> *superloops;
142 /* The first inner (child) loop or NULL if innermost loop. */
143 struct loop *inner;
145 /* Link to the next (sibling) loop. */
146 struct loop *next;
148 /* Auxiliary info specific to a pass. */
149 PTR GTY ((skip (""))) aux;
151 /* The number of times the latch of the loop is executed. This can be an
152 INTEGER_CST, or a symbolic expression representing the number of
153 iterations like "N - 1", or a COND_EXPR containing the runtime
154 conditions under which the number of iterations is non zero.
156 Don't access this field directly: number_of_latch_executions
157 computes and caches the computed information in this field. */
158 tree nb_iterations;
160 /* An integer guaranteed to be greater or equal to nb_iterations. Only
161 valid if any_upper_bound is true. */
162 widest_int nb_iterations_upper_bound;
164 widest_int nb_iterations_likely_upper_bound;
166 /* An integer giving an estimate on nb_iterations. Unlike
167 nb_iterations_upper_bound, there is no guarantee that it is at least
168 nb_iterations. */
169 widest_int nb_iterations_estimate;
171 /* If > 0, an integer, where the user asserted that for any
172 I in [ 0, nb_iterations ) and for any J in
173 [ I, min ( I + safelen, nb_iterations ) ), the Ith and Jth iterations
174 of the loop can be safely evaluated concurrently. */
175 int safelen;
177 /* Constraints are generally set by consumers and affect certain
178 semantics of niter analyzer APIs. Currently the APIs affected are
179 number_of_iterations_exit* functions and their callers. One typical
180 use case of constraints is to vectorize possibly infinite loop:
182 1) Compute niter->assumptions by calling niter analyzer API and
183 record it as possible condition for loop versioning.
184 2) Clear buffered result of niter/scev analyzer.
185 3) Set constraint LOOP_C_FINITE assuming the loop is finite.
186 4) Analyze data references. Since data reference analysis depends
187 on niter/scev analyzer, the point is that niter/scev analysis
188 is done under circumstance of LOOP_C_FINITE constraint.
189 5) Version the loop with niter->assumptions computed in step 1).
190 6) Vectorize the versioned loop in which niter->assumptions is
191 checked to be true.
192 7) Update constraints in versioned loops so that niter analyzer
193 in following passes can use it.
195 Note consumers are usually the loop optimizers and it is consumers'
196 responsibility to set/clear constraints correctly. Failing to do
197 that might result in hard to track down bugs in niter/scev consumers. */
198 unsigned constraints;
200 /* An integer estimation of the number of iterations. Estimate_state
201 describes what is the state of the estimation. */
202 ENUM_BITFIELD(loop_estimation) estimate_state : 8;
204 unsigned any_upper_bound : 1;
205 unsigned any_estimate : 1;
206 unsigned any_likely_upper_bound : 1;
208 /* True if the loop can be parallel. */
209 unsigned can_be_parallel : 1;
211 /* True if -Waggressive-loop-optimizations warned about this loop
212 already. */
213 unsigned warned_aggressive_loop_optimizations : 1;
215 /* True if this loop should never be vectorized. */
216 unsigned dont_vectorize : 1;
218 /* True if we should try harder to vectorize this loop. */
219 unsigned force_vectorize : 1;
221 /* True if the loop is part of an oacc kernels region. */
222 unsigned in_oacc_kernels_region : 1;
224 /* For SIMD loops, this is a unique identifier of the loop, referenced
225 by IFN_GOMP_SIMD_VF, IFN_GOMP_SIMD_LANE and IFN_GOMP_SIMD_LAST_LANE
226 builtins. */
227 tree simduid;
229 /* In loop optimization, it's common to generate loops from the original
230 loop. This field records the index of the original loop which can be
231 used to track the original loop from newly generated loops. This can
232 be done by calling function get_loop (cfun, orig_loop_num). Note the
233 original loop could be destroyed for various reasons thus no longer
234 exists, as a result, function call to get_loop returns NULL pointer.
235 In this case, this field should not be used and needs to be cleared
236 whenever possible. */
237 int orig_loop_num;
239 /* Upper bound on number of iterations of a loop. */
240 struct nb_iter_bound *bounds;
242 /* Non-overflow control ivs of a loop. */
243 struct control_iv *control_ivs;
245 /* Head of the cyclic list of the exits of the loop. */
246 struct loop_exit *exits;
248 /* Number of iteration analysis data for RTL. */
249 struct niter_desc *simple_loop_desc;
251 /* For sanity checking during loop fixup we record here the former
252 loop header for loops marked for removal. Note that this prevents
253 the basic-block from being collected but its index can still be
254 reused. */
255 basic_block former_header;
258 /* Set if the loop is known to be infinite. */
259 #define LOOP_C_INFINITE (1 << 0)
260 /* Set if the loop is known to be finite without any assumptions. */
261 #define LOOP_C_FINITE (1 << 1)
263 /* Set C to the LOOP constraint. */
264 static inline void
265 loop_constraint_set (struct loop *loop, unsigned c)
267 loop->constraints |= c;
270 /* Clear C from the LOOP constraint. */
271 static inline void
272 loop_constraint_clear (struct loop *loop, unsigned c)
274 loop->constraints &= ~c;
277 /* Check if C is set in the LOOP constraint. */
278 static inline bool
279 loop_constraint_set_p (struct loop *loop, unsigned c)
281 return (loop->constraints & c) == c;
284 /* Flags for state of loop structure. */
285 enum
287 LOOPS_HAVE_PREHEADERS = 1,
288 LOOPS_HAVE_SIMPLE_LATCHES = 2,
289 LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS = 4,
290 LOOPS_HAVE_RECORDED_EXITS = 8,
291 LOOPS_MAY_HAVE_MULTIPLE_LATCHES = 16,
292 LOOP_CLOSED_SSA = 32,
293 LOOPS_NEED_FIXUP = 64,
294 LOOPS_HAVE_FALLTHRU_PREHEADERS = 128
297 #define LOOPS_NORMAL (LOOPS_HAVE_PREHEADERS | LOOPS_HAVE_SIMPLE_LATCHES \
298 | LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)
299 #define AVOID_CFG_MODIFICATIONS (LOOPS_MAY_HAVE_MULTIPLE_LATCHES)
301 /* Structure to hold CFG information about natural loops within a function. */
302 struct GTY (()) loops {
303 /* State of loops. */
304 int state;
306 /* Array of the loops. */
307 vec<loop_p, va_gc> *larray;
309 /* Maps edges to the list of their descriptions as loop exits. Edges
310 whose sources or destinations have loop_father == NULL (which may
311 happen during the cfg manipulations) should not appear in EXITS. */
312 hash_table<loop_exit_hasher> *GTY(()) exits;
314 /* Pointer to root of loop hierarchy tree. */
315 struct loop *tree_root;
318 /* Loop recognition. */
319 bool bb_loop_header_p (basic_block);
320 void init_loops_structure (struct function *, struct loops *, unsigned);
321 extern struct loops *flow_loops_find (struct loops *);
322 extern void disambiguate_loops_with_multiple_latches (void);
323 extern void flow_loops_free (struct loops *);
324 extern void flow_loops_dump (FILE *,
325 void (*)(const struct loop *, FILE *, int), int);
326 extern void flow_loop_dump (const struct loop *, FILE *,
327 void (*)(const struct loop *, FILE *, int), int);
328 struct loop *alloc_loop (void);
329 extern void flow_loop_free (struct loop *);
330 int flow_loop_nodes_find (basic_block, struct loop *);
331 unsigned fix_loop_structure (bitmap changed_bbs);
332 bool mark_irreducible_loops (void);
333 void release_recorded_exits (function *);
334 void record_loop_exits (void);
335 void rescan_loop_exit (edge, bool, bool);
337 /* Loop data structure manipulation/querying. */
338 extern void flow_loop_tree_node_add (struct loop *, struct loop *);
339 extern void flow_loop_tree_node_remove (struct loop *);
340 extern bool flow_loop_nested_p (const struct loop *, const struct loop *);
341 extern bool flow_bb_inside_loop_p (const struct loop *, const_basic_block);
342 extern struct loop * find_common_loop (struct loop *, struct loop *);
343 struct loop *superloop_at_depth (struct loop *, unsigned);
344 struct eni_weights;
345 extern int num_loop_insns (const struct loop *);
346 extern int average_num_loop_insns (const struct loop *);
347 extern unsigned get_loop_level (const struct loop *);
348 extern bool loop_exit_edge_p (const struct loop *, const_edge);
349 extern bool loop_exits_to_bb_p (struct loop *, basic_block);
350 extern bool loop_exits_from_bb_p (struct loop *, basic_block);
351 extern void mark_loop_exit_edges (void);
352 extern location_t get_loop_location (struct loop *loop);
354 /* Loops & cfg manipulation. */
355 extern basic_block *get_loop_body (const struct loop *);
356 extern unsigned get_loop_body_with_size (const struct loop *, basic_block *,
357 unsigned);
358 extern basic_block *get_loop_body_in_dom_order (const struct loop *);
359 extern basic_block *get_loop_body_in_bfs_order (const struct loop *);
360 extern basic_block *get_loop_body_in_custom_order (const struct loop *,
361 int (*) (const void *, const void *));
363 extern vec<edge> get_loop_exit_edges (const struct loop *);
364 extern edge single_exit (const struct loop *);
365 extern edge single_likely_exit (struct loop *loop);
366 extern unsigned num_loop_branches (const struct loop *);
368 extern edge loop_preheader_edge (const struct loop *);
369 extern edge loop_latch_edge (const struct loop *);
371 extern void add_bb_to_loop (basic_block, struct loop *);
372 extern void remove_bb_from_loops (basic_block);
374 extern void cancel_loop_tree (struct loop *);
375 extern void delete_loop (struct loop *);
378 extern void verify_loop_structure (void);
380 /* Loop analysis. */
381 extern bool just_once_each_iteration_p (const struct loop *, const_basic_block);
382 gcov_type expected_loop_iterations_unbounded (const struct loop *,
383 bool *read_profile_p = NULL);
384 extern unsigned expected_loop_iterations (struct loop *);
385 extern rtx doloop_condition_get (rtx_insn *);
387 void mark_loop_for_removal (loop_p);
389 /* Induction variable analysis. */
391 /* The description of induction variable. The things are a bit complicated
392 due to need to handle subregs and extends. The value of the object described
393 by it can be obtained as follows (all computations are done in extend_mode):
395 Value in i-th iteration is
396 delta + mult * extend_{extend_mode} (subreg_{mode} (base + i * step)).
398 If first_special is true, the value in the first iteration is
399 delta + mult * base
401 If extend = UNKNOWN, first_special must be false, delta 0, mult 1 and value is
402 subreg_{mode} (base + i * step)
404 The get_iv_value function can be used to obtain these expressions.
406 ??? Add a third mode field that would specify the mode in that inner
407 computation is done, which would enable it to be different from the
408 outer one? */
410 struct rtx_iv
412 /* Its base and step (mode of base and step is supposed to be extend_mode,
413 see the description above). */
414 rtx base, step;
416 /* The type of extend applied to it (IV_SIGN_EXTEND, IV_ZERO_EXTEND,
417 or IV_UNKNOWN_EXTEND). */
418 enum iv_extend_code extend;
420 /* Operations applied in the extended mode. */
421 rtx delta, mult;
423 /* The mode it is extended to. */
424 scalar_int_mode extend_mode;
426 /* The mode the variable iterates in. */
427 scalar_int_mode mode;
429 /* Whether the first iteration needs to be handled specially. */
430 unsigned first_special : 1;
433 /* The description of an exit from the loop and of the number of iterations
434 till we take the exit. */
436 struct GTY(()) niter_desc
438 /* The edge out of the loop. */
439 edge out_edge;
441 /* The other edge leading from the condition. */
442 edge in_edge;
444 /* True if we are able to say anything about number of iterations of the
445 loop. */
446 bool simple_p;
448 /* True if the loop iterates the constant number of times. */
449 bool const_iter;
451 /* Number of iterations if constant. */
452 uint64_t niter;
454 /* Assumptions under that the rest of the information is valid. */
455 rtx assumptions;
457 /* Assumptions under that the loop ends before reaching the latch,
458 even if value of niter_expr says otherwise. */
459 rtx noloop_assumptions;
461 /* Condition under that the loop is infinite. */
462 rtx infinite;
464 /* Whether the comparison is signed. */
465 bool signed_p;
467 /* The mode in that niter_expr should be computed. */
468 scalar_int_mode mode;
470 /* The number of iterations of the loop. */
471 rtx niter_expr;
474 extern void iv_analysis_loop_init (struct loop *);
475 extern bool iv_analyze (rtx_insn *, scalar_int_mode, rtx, struct rtx_iv *);
476 extern bool iv_analyze_result (rtx_insn *, rtx, struct rtx_iv *);
477 extern bool iv_analyze_expr (rtx_insn *, scalar_int_mode, rtx,
478 struct rtx_iv *);
479 extern rtx get_iv_value (struct rtx_iv *, rtx);
480 extern bool biv_p (rtx_insn *, scalar_int_mode, rtx);
481 extern void find_simple_exit (struct loop *, struct niter_desc *);
482 extern void iv_analysis_done (void);
484 extern struct niter_desc *get_simple_loop_desc (struct loop *loop);
485 extern void free_simple_loop_desc (struct loop *loop);
487 static inline struct niter_desc *
488 simple_loop_desc (struct loop *loop)
490 return loop->simple_loop_desc;
493 /* Accessors for the loop structures. */
495 /* Returns the loop with index NUM from FNs loop tree. */
497 static inline struct loop *
498 get_loop (struct function *fn, unsigned num)
500 return (*loops_for_fn (fn)->larray)[num];
503 /* Returns the number of superloops of LOOP. */
505 static inline unsigned
506 loop_depth (const struct loop *loop)
508 return vec_safe_length (loop->superloops);
511 /* Returns the immediate superloop of LOOP, or NULL if LOOP is the outermost
512 loop. */
514 static inline struct loop *
515 loop_outer (const struct loop *loop)
517 unsigned n = vec_safe_length (loop->superloops);
519 if (n == 0)
520 return NULL;
522 return (*loop->superloops)[n - 1];
525 /* Returns true if LOOP has at least one exit edge. */
527 static inline bool
528 loop_has_exit_edges (const struct loop *loop)
530 return loop->exits->next->e != NULL;
533 /* Returns the list of loops in FN. */
535 inline vec<loop_p, va_gc> *
536 get_loops (struct function *fn)
538 struct loops *loops = loops_for_fn (fn);
539 if (!loops)
540 return NULL;
542 return loops->larray;
545 /* Returns the number of loops in FN (including the removed
546 ones and the fake loop that forms the root of the loop tree). */
548 static inline unsigned
549 number_of_loops (struct function *fn)
551 struct loops *loops = loops_for_fn (fn);
552 if (!loops)
553 return 0;
555 return vec_safe_length (loops->larray);
558 /* Returns true if state of the loops satisfies all properties
559 described by FLAGS. */
561 static inline bool
562 loops_state_satisfies_p (function *fn, unsigned flags)
564 return (loops_for_fn (fn)->state & flags) == flags;
567 static inline bool
568 loops_state_satisfies_p (unsigned flags)
570 return loops_state_satisfies_p (cfun, flags);
573 /* Sets FLAGS to the loops state. */
575 static inline void
576 loops_state_set (function *fn, unsigned flags)
578 loops_for_fn (fn)->state |= flags;
581 static inline void
582 loops_state_set (unsigned flags)
584 loops_state_set (cfun, flags);
587 /* Clears FLAGS from the loops state. */
589 static inline void
590 loops_state_clear (function *fn, unsigned flags)
592 loops_for_fn (fn)->state &= ~flags;
595 static inline void
596 loops_state_clear (unsigned flags)
598 if (!current_loops)
599 return;
600 loops_state_clear (cfun, flags);
603 /* Check loop structure invariants, if internal consistency checks are
604 enabled. */
606 static inline void
607 checking_verify_loop_structure (void)
609 /* VERIFY_LOOP_STRUCTURE essentially asserts that no loops need fixups.
611 The loop optimizers should never make changes to the CFG which
612 require loop fixups. But the low level CFG manipulation code may
613 set the flag conservatively.
615 Go ahead and clear the flag here. That avoids the assert inside
616 VERIFY_LOOP_STRUCTURE, and if there is an inconsistency in the loop
617 structures VERIFY_LOOP_STRUCTURE will detect it.
619 This also avoid the compile time cost of excessive fixups. */
620 loops_state_clear (LOOPS_NEED_FIXUP);
621 if (flag_checking)
622 verify_loop_structure ();
625 /* Loop iterators. */
627 /* Flags for loop iteration. */
629 enum li_flags
631 LI_INCLUDE_ROOT = 1, /* Include the fake root of the loop tree. */
632 LI_FROM_INNERMOST = 2, /* Iterate over the loops in the reverse order,
633 starting from innermost ones. */
634 LI_ONLY_INNERMOST = 4 /* Iterate only over innermost loops. */
637 /* The iterator for loops. */
639 struct loop_iterator
641 loop_iterator (function *fn, loop_p *loop, unsigned flags);
642 ~loop_iterator ();
644 inline loop_p next ();
646 /* The function we are visiting. */
647 function *fn;
649 /* The list of loops to visit. */
650 vec<int> to_visit;
652 /* The index of the actual loop. */
653 unsigned idx;
656 inline loop_p
657 loop_iterator::next ()
659 int anum;
661 while (this->to_visit.iterate (this->idx, &anum))
663 this->idx++;
664 loop_p loop = get_loop (fn, anum);
665 if (loop)
666 return loop;
669 return NULL;
672 inline
673 loop_iterator::loop_iterator (function *fn, loop_p *loop, unsigned flags)
675 struct loop *aloop;
676 unsigned i;
677 int mn;
679 this->idx = 0;
680 this->fn = fn;
681 if (!loops_for_fn (fn))
683 this->to_visit.create (0);
684 *loop = NULL;
685 return;
688 this->to_visit.create (number_of_loops (fn));
689 mn = (flags & LI_INCLUDE_ROOT) ? 0 : 1;
691 if (flags & LI_ONLY_INNERMOST)
693 for (i = 0; vec_safe_iterate (loops_for_fn (fn)->larray, i, &aloop); i++)
694 if (aloop != NULL
695 && aloop->inner == NULL
696 && aloop->num >= mn)
697 this->to_visit.quick_push (aloop->num);
699 else if (flags & LI_FROM_INNERMOST)
701 /* Push the loops to LI->TO_VISIT in postorder. */
702 for (aloop = loops_for_fn (fn)->tree_root;
703 aloop->inner != NULL;
704 aloop = aloop->inner)
705 continue;
707 while (1)
709 if (aloop->num >= mn)
710 this->to_visit.quick_push (aloop->num);
712 if (aloop->next)
714 for (aloop = aloop->next;
715 aloop->inner != NULL;
716 aloop = aloop->inner)
717 continue;
719 else if (!loop_outer (aloop))
720 break;
721 else
722 aloop = loop_outer (aloop);
725 else
727 /* Push the loops to LI->TO_VISIT in preorder. */
728 aloop = loops_for_fn (fn)->tree_root;
729 while (1)
731 if (aloop->num >= mn)
732 this->to_visit.quick_push (aloop->num);
734 if (aloop->inner != NULL)
735 aloop = aloop->inner;
736 else
738 while (aloop != NULL && aloop->next == NULL)
739 aloop = loop_outer (aloop);
740 if (aloop == NULL)
741 break;
742 aloop = aloop->next;
747 *loop = this->next ();
750 inline
751 loop_iterator::~loop_iterator ()
753 this->to_visit.release ();
756 #define FOR_EACH_LOOP(LOOP, FLAGS) \
757 for (loop_iterator li(cfun, &(LOOP), FLAGS); \
758 (LOOP); \
759 (LOOP) = li.next ())
761 #define FOR_EACH_LOOP_FN(FN, LOOP, FLAGS) \
762 for (loop_iterator li(fn, &(LOOP), FLAGS); \
763 (LOOP); \
764 (LOOP) = li.next ())
766 /* The properties of the target. */
767 struct target_cfgloop {
768 /* Number of available registers. */
769 unsigned x_target_avail_regs;
771 /* Number of available registers that are call-clobbered. */
772 unsigned x_target_clobbered_regs;
774 /* Number of registers reserved for temporary expressions. */
775 unsigned x_target_res_regs;
777 /* The cost for register when there still is some reserve, but we are
778 approaching the number of available registers. */
779 unsigned x_target_reg_cost[2];
781 /* The cost for register when we need to spill. */
782 unsigned x_target_spill_cost[2];
785 extern struct target_cfgloop default_target_cfgloop;
786 #if SWITCHABLE_TARGET
787 extern struct target_cfgloop *this_target_cfgloop;
788 #else
789 #define this_target_cfgloop (&default_target_cfgloop)
790 #endif
792 #define target_avail_regs \
793 (this_target_cfgloop->x_target_avail_regs)
794 #define target_clobbered_regs \
795 (this_target_cfgloop->x_target_clobbered_regs)
796 #define target_res_regs \
797 (this_target_cfgloop->x_target_res_regs)
798 #define target_reg_cost \
799 (this_target_cfgloop->x_target_reg_cost)
800 #define target_spill_cost \
801 (this_target_cfgloop->x_target_spill_cost)
803 /* Register pressure estimation for induction variable optimizations & loop
804 invariant motion. */
805 extern unsigned estimate_reg_pressure_cost (unsigned, unsigned, bool, bool);
806 extern void init_set_costs (void);
808 /* Loop optimizer initialization. */
809 extern void loop_optimizer_init (unsigned);
810 extern void loop_optimizer_finalize (function *);
811 inline void
812 loop_optimizer_finalize ()
814 loop_optimizer_finalize (cfun);
817 /* Optimization passes. */
818 enum
820 UAP_UNROLL = 1, /* Enables unrolling of loops if it seems profitable. */
821 UAP_UNROLL_ALL = 2 /* Enables unrolling of all loops. */
824 extern void doloop_optimize_loops (void);
825 extern void move_loop_invariants (void);
826 extern vec<basic_block> get_loop_hot_path (const struct loop *loop);
828 /* Returns the outermost loop of the loop nest that contains LOOP.*/
829 static inline struct loop *
830 loop_outermost (struct loop *loop)
832 unsigned n = vec_safe_length (loop->superloops);
834 if (n <= 1)
835 return loop;
837 return (*loop->superloops)[1];
840 extern void record_niter_bound (struct loop *, const widest_int &, bool, bool);
841 extern HOST_WIDE_INT get_estimated_loop_iterations_int (struct loop *);
842 extern HOST_WIDE_INT get_max_loop_iterations_int (const struct loop *);
843 extern HOST_WIDE_INT get_likely_max_loop_iterations_int (struct loop *);
844 extern bool get_estimated_loop_iterations (struct loop *loop, widest_int *nit);
845 extern bool get_max_loop_iterations (const struct loop *loop, widest_int *nit);
846 extern bool get_likely_max_loop_iterations (struct loop *loop, widest_int *nit);
847 extern int bb_loop_depth (const_basic_block);
849 /* Converts VAL to widest_int. */
851 static inline widest_int
852 gcov_type_to_wide_int (gcov_type val)
854 HOST_WIDE_INT a[2];
856 a[0] = (unsigned HOST_WIDE_INT) val;
857 /* If HOST_BITS_PER_WIDE_INT == HOST_BITS_PER_WIDEST_INT, avoid shifting by
858 the size of type. */
859 val >>= HOST_BITS_PER_WIDE_INT - 1;
860 val >>= 1;
861 a[1] = (unsigned HOST_WIDE_INT) val;
863 return widest_int::from_array (a, 2);
865 #endif /* GCC_CFGLOOP_H */