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
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
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/>. */
23 #include "cfgloopmanip.h"
25 /* Structure to hold decision about unrolling/peeling. */
34 struct GTY (()) lpt_decision
{
35 enum lpt_dec decision
;
39 /* The type of extend applied to an IV. */
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 ... */
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. */
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. */
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
{
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. */
100 /* Estimate was not computed yet. */
102 /* Estimate is ready. */
107 /* The structure describing non-overflow control induction variable for
109 struct GTY ((chain_next ("%h.next"))) control_iv
{
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
121 /* Number of loop insns. */
124 /* Basic block of loop header. */
127 /* Basic block of loop latch. */
130 /* For loop unrolling/peeling decision. */
131 struct lpt_decision lpt_decision
;
133 /* Average number of executed insns per iteration. */
136 /* Number of blocks contained within the loop. */
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. */
145 /* Link to the next (sibling) loop. */
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. */
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
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. */
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
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
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 /* The number of times to unroll the loop. 0, means no information
225 given, just do what we always do. A value of 1, means don't unroll
227 unsigned short unroll
;
229 /* For SIMD loops, this is a unique identifier of the loop, referenced
230 by IFN_GOMP_SIMD_VF, IFN_GOMP_SIMD_LANE and IFN_GOMP_SIMD_LAST_LANE
234 /* In loop optimization, it's common to generate loops from the original
235 loop. This field records the index of the original loop which can be
236 used to track the original loop from newly generated loops. This can
237 be done by calling function get_loop (cfun, orig_loop_num). Note the
238 original loop could be destroyed for various reasons thus no longer
239 exists, as a result, function call to get_loop returns NULL pointer.
240 In this case, this field should not be used and needs to be cleared
241 whenever possible. */
244 /* Upper bound on number of iterations of a loop. */
245 struct nb_iter_bound
*bounds
;
247 /* Non-overflow control ivs of a loop. */
248 struct control_iv
*control_ivs
;
250 /* Head of the cyclic list of the exits of the loop. */
251 struct loop_exit
*exits
;
253 /* Number of iteration analysis data for RTL. */
254 struct niter_desc
*simple_loop_desc
;
256 /* For sanity checking during loop fixup we record here the former
257 loop header for loops marked for removal. Note that this prevents
258 the basic-block from being collected but its index can still be
260 basic_block former_header
;
263 /* Set if the loop is known to be infinite. */
264 #define LOOP_C_INFINITE (1 << 0)
265 /* Set if the loop is known to be finite without any assumptions. */
266 #define LOOP_C_FINITE (1 << 1)
268 /* Set C to the LOOP constraint. */
270 loop_constraint_set (struct loop
*loop
, unsigned c
)
272 loop
->constraints
|= c
;
275 /* Clear C from the LOOP constraint. */
277 loop_constraint_clear (struct loop
*loop
, unsigned c
)
279 loop
->constraints
&= ~c
;
282 /* Check if C is set in the LOOP constraint. */
284 loop_constraint_set_p (struct loop
*loop
, unsigned c
)
286 return (loop
->constraints
& c
) == c
;
289 /* Flags for state of loop structure. */
292 LOOPS_HAVE_PREHEADERS
= 1,
293 LOOPS_HAVE_SIMPLE_LATCHES
= 2,
294 LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS
= 4,
295 LOOPS_HAVE_RECORDED_EXITS
= 8,
296 LOOPS_MAY_HAVE_MULTIPLE_LATCHES
= 16,
297 LOOP_CLOSED_SSA
= 32,
298 LOOPS_NEED_FIXUP
= 64,
299 LOOPS_HAVE_FALLTHRU_PREHEADERS
= 128
302 #define LOOPS_NORMAL (LOOPS_HAVE_PREHEADERS | LOOPS_HAVE_SIMPLE_LATCHES \
303 | LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)
304 #define AVOID_CFG_MODIFICATIONS (LOOPS_MAY_HAVE_MULTIPLE_LATCHES)
306 /* Structure to hold CFG information about natural loops within a function. */
307 struct GTY (()) loops
{
308 /* State of loops. */
311 /* Array of the loops. */
312 vec
<loop_p
, va_gc
> *larray
;
314 /* Maps edges to the list of their descriptions as loop exits. Edges
315 whose sources or destinations have loop_father == NULL (which may
316 happen during the cfg manipulations) should not appear in EXITS. */
317 hash_table
<loop_exit_hasher
> *GTY(()) exits
;
319 /* Pointer to root of loop hierarchy tree. */
320 struct loop
*tree_root
;
323 /* Loop recognition. */
324 bool bb_loop_header_p (basic_block
);
325 void init_loops_structure (struct function
*, struct loops
*, unsigned);
326 extern struct loops
*flow_loops_find (struct loops
*);
327 extern void disambiguate_loops_with_multiple_latches (void);
328 extern void flow_loops_free (struct loops
*);
329 extern void flow_loops_dump (FILE *,
330 void (*)(const struct loop
*, FILE *, int), int);
331 extern void flow_loop_dump (const struct loop
*, FILE *,
332 void (*)(const struct loop
*, FILE *, int), int);
333 struct loop
*alloc_loop (void);
334 extern void flow_loop_free (struct loop
*);
335 int flow_loop_nodes_find (basic_block
, struct loop
*);
336 unsigned fix_loop_structure (bitmap changed_bbs
);
337 bool mark_irreducible_loops (void);
338 void release_recorded_exits (function
*);
339 void record_loop_exits (void);
340 void rescan_loop_exit (edge
, bool, bool);
341 void sort_sibling_loops (function
*);
343 /* Loop data structure manipulation/querying. */
344 extern void flow_loop_tree_node_add (struct loop
*, struct loop
*);
345 extern void flow_loop_tree_node_remove (struct loop
*);
346 extern bool flow_loop_nested_p (const struct loop
*, const struct loop
*);
347 extern bool flow_bb_inside_loop_p (const struct loop
*, const_basic_block
);
348 extern struct loop
* find_common_loop (struct loop
*, struct loop
*);
349 struct loop
*superloop_at_depth (struct loop
*, unsigned);
351 extern int num_loop_insns (const struct loop
*);
352 extern int average_num_loop_insns (const struct loop
*);
353 extern unsigned get_loop_level (const struct loop
*);
354 extern bool loop_exit_edge_p (const struct loop
*, const_edge
);
355 extern bool loop_exits_to_bb_p (struct loop
*, basic_block
);
356 extern bool loop_exits_from_bb_p (struct loop
*, basic_block
);
357 extern void mark_loop_exit_edges (void);
358 extern location_t
get_loop_location (struct loop
*loop
);
360 /* Loops & cfg manipulation. */
361 extern basic_block
*get_loop_body (const struct loop
*);
362 extern unsigned get_loop_body_with_size (const struct loop
*, basic_block
*,
364 extern basic_block
*get_loop_body_in_dom_order (const struct loop
*);
365 extern basic_block
*get_loop_body_in_bfs_order (const struct loop
*);
366 extern basic_block
*get_loop_body_in_custom_order (const struct loop
*,
367 int (*) (const void *, const void *));
369 extern vec
<edge
> get_loop_exit_edges (const struct loop
*);
370 extern edge
single_exit (const struct loop
*);
371 extern edge
single_likely_exit (struct loop
*loop
);
372 extern unsigned num_loop_branches (const struct loop
*);
374 extern edge
loop_preheader_edge (const struct loop
*);
375 extern edge
loop_latch_edge (const struct loop
*);
377 extern void add_bb_to_loop (basic_block
, struct loop
*);
378 extern void remove_bb_from_loops (basic_block
);
380 extern void cancel_loop_tree (struct loop
*);
381 extern void delete_loop (struct loop
*);
384 extern void verify_loop_structure (void);
387 extern bool just_once_each_iteration_p (const struct loop
*, const_basic_block
);
388 gcov_type
expected_loop_iterations_unbounded (const struct loop
*,
389 bool *read_profile_p
= NULL
);
390 extern unsigned expected_loop_iterations (struct loop
*);
391 extern rtx
doloop_condition_get (rtx_insn
*);
393 void mark_loop_for_removal (loop_p
);
395 /* Induction variable analysis. */
397 /* The description of induction variable. The things are a bit complicated
398 due to need to handle subregs and extends. The value of the object described
399 by it can be obtained as follows (all computations are done in extend_mode):
401 Value in i-th iteration is
402 delta + mult * extend_{extend_mode} (subreg_{mode} (base + i * step)).
404 If first_special is true, the value in the first iteration is
407 If extend = UNKNOWN, first_special must be false, delta 0, mult 1 and value is
408 subreg_{mode} (base + i * step)
410 The get_iv_value function can be used to obtain these expressions.
412 ??? Add a third mode field that would specify the mode in that inner
413 computation is done, which would enable it to be different from the
418 /* Its base and step (mode of base and step is supposed to be extend_mode,
419 see the description above). */
422 /* The type of extend applied to it (IV_SIGN_EXTEND, IV_ZERO_EXTEND,
423 or IV_UNKNOWN_EXTEND). */
424 enum iv_extend_code extend
;
426 /* Operations applied in the extended mode. */
429 /* The mode it is extended to. */
430 scalar_int_mode extend_mode
;
432 /* The mode the variable iterates in. */
433 scalar_int_mode mode
;
435 /* Whether the first iteration needs to be handled specially. */
436 unsigned first_special
: 1;
439 /* The description of an exit from the loop and of the number of iterations
440 till we take the exit. */
442 struct GTY(()) niter_desc
444 /* The edge out of the loop. */
447 /* The other edge leading from the condition. */
450 /* True if we are able to say anything about number of iterations of the
454 /* True if the loop iterates the constant number of times. */
457 /* Number of iterations if constant. */
460 /* Assumptions under that the rest of the information is valid. */
463 /* Assumptions under that the loop ends before reaching the latch,
464 even if value of niter_expr says otherwise. */
465 rtx noloop_assumptions
;
467 /* Condition under that the loop is infinite. */
470 /* Whether the comparison is signed. */
473 /* The mode in that niter_expr should be computed. */
474 scalar_int_mode mode
;
476 /* The number of iterations of the loop. */
480 extern void iv_analysis_loop_init (struct loop
*);
481 extern bool iv_analyze (rtx_insn
*, scalar_int_mode
, rtx
, struct rtx_iv
*);
482 extern bool iv_analyze_result (rtx_insn
*, rtx
, struct rtx_iv
*);
483 extern bool iv_analyze_expr (rtx_insn
*, scalar_int_mode
, rtx
,
485 extern rtx
get_iv_value (struct rtx_iv
*, rtx
);
486 extern bool biv_p (rtx_insn
*, scalar_int_mode
, rtx
);
487 extern void find_simple_exit (struct loop
*, struct niter_desc
*);
488 extern void iv_analysis_done (void);
490 extern struct niter_desc
*get_simple_loop_desc (struct loop
*loop
);
491 extern void free_simple_loop_desc (struct loop
*loop
);
493 static inline struct niter_desc
*
494 simple_loop_desc (struct loop
*loop
)
496 return loop
->simple_loop_desc
;
499 /* Accessors for the loop structures. */
501 /* Returns the loop with index NUM from FNs loop tree. */
503 static inline struct loop
*
504 get_loop (struct function
*fn
, unsigned num
)
506 return (*loops_for_fn (fn
)->larray
)[num
];
509 /* Returns the number of superloops of LOOP. */
511 static inline unsigned
512 loop_depth (const struct loop
*loop
)
514 return vec_safe_length (loop
->superloops
);
517 /* Returns the immediate superloop of LOOP, or NULL if LOOP is the outermost
520 static inline struct loop
*
521 loop_outer (const struct loop
*loop
)
523 unsigned n
= vec_safe_length (loop
->superloops
);
528 return (*loop
->superloops
)[n
- 1];
531 /* Returns true if LOOP has at least one exit edge. */
534 loop_has_exit_edges (const struct loop
*loop
)
536 return loop
->exits
->next
->e
!= NULL
;
539 /* Returns the list of loops in FN. */
541 inline vec
<loop_p
, va_gc
> *
542 get_loops (struct function
*fn
)
544 struct loops
*loops
= loops_for_fn (fn
);
548 return loops
->larray
;
551 /* Returns the number of loops in FN (including the removed
552 ones and the fake loop that forms the root of the loop tree). */
554 static inline unsigned
555 number_of_loops (struct function
*fn
)
557 struct loops
*loops
= loops_for_fn (fn
);
561 return vec_safe_length (loops
->larray
);
564 /* Returns true if state of the loops satisfies all properties
565 described by FLAGS. */
568 loops_state_satisfies_p (function
*fn
, unsigned flags
)
570 return (loops_for_fn (fn
)->state
& flags
) == flags
;
574 loops_state_satisfies_p (unsigned flags
)
576 return loops_state_satisfies_p (cfun
, flags
);
579 /* Sets FLAGS to the loops state. */
582 loops_state_set (function
*fn
, unsigned flags
)
584 loops_for_fn (fn
)->state
|= flags
;
588 loops_state_set (unsigned flags
)
590 loops_state_set (cfun
, flags
);
593 /* Clears FLAGS from the loops state. */
596 loops_state_clear (function
*fn
, unsigned flags
)
598 loops_for_fn (fn
)->state
&= ~flags
;
602 loops_state_clear (unsigned flags
)
606 loops_state_clear (cfun
, flags
);
609 /* Check loop structure invariants, if internal consistency checks are
613 checking_verify_loop_structure (void)
615 /* VERIFY_LOOP_STRUCTURE essentially asserts that no loops need fixups.
617 The loop optimizers should never make changes to the CFG which
618 require loop fixups. But the low level CFG manipulation code may
619 set the flag conservatively.
621 Go ahead and clear the flag here. That avoids the assert inside
622 VERIFY_LOOP_STRUCTURE, and if there is an inconsistency in the loop
623 structures VERIFY_LOOP_STRUCTURE will detect it.
625 This also avoid the compile time cost of excessive fixups. */
626 loops_state_clear (LOOPS_NEED_FIXUP
);
628 verify_loop_structure ();
631 /* Loop iterators. */
633 /* Flags for loop iteration. */
637 LI_INCLUDE_ROOT
= 1, /* Include the fake root of the loop tree. */
638 LI_FROM_INNERMOST
= 2, /* Iterate over the loops in the reverse order,
639 starting from innermost ones. */
640 LI_ONLY_INNERMOST
= 4 /* Iterate only over innermost loops. */
643 /* The iterator for loops. */
647 loop_iterator (function
*fn
, loop_p
*loop
, unsigned flags
);
650 inline loop_p
next ();
652 /* The function we are visiting. */
655 /* The list of loops to visit. */
658 /* The index of the actual loop. */
663 loop_iterator::next ()
667 while (this->to_visit
.iterate (this->idx
, &anum
))
670 loop_p loop
= get_loop (fn
, anum
);
679 loop_iterator::loop_iterator (function
*fn
, loop_p
*loop
, unsigned flags
)
687 if (!loops_for_fn (fn
))
689 this->to_visit
.create (0);
694 this->to_visit
.create (number_of_loops (fn
));
695 mn
= (flags
& LI_INCLUDE_ROOT
) ? 0 : 1;
697 if (flags
& LI_ONLY_INNERMOST
)
699 for (i
= 0; vec_safe_iterate (loops_for_fn (fn
)->larray
, i
, &aloop
); i
++)
701 && aloop
->inner
== NULL
703 this->to_visit
.quick_push (aloop
->num
);
705 else if (flags
& LI_FROM_INNERMOST
)
707 /* Push the loops to LI->TO_VISIT in postorder. */
708 for (aloop
= loops_for_fn (fn
)->tree_root
;
709 aloop
->inner
!= NULL
;
710 aloop
= aloop
->inner
)
715 if (aloop
->num
>= mn
)
716 this->to_visit
.quick_push (aloop
->num
);
720 for (aloop
= aloop
->next
;
721 aloop
->inner
!= NULL
;
722 aloop
= aloop
->inner
)
725 else if (!loop_outer (aloop
))
728 aloop
= loop_outer (aloop
);
733 /* Push the loops to LI->TO_VISIT in preorder. */
734 aloop
= loops_for_fn (fn
)->tree_root
;
737 if (aloop
->num
>= mn
)
738 this->to_visit
.quick_push (aloop
->num
);
740 if (aloop
->inner
!= NULL
)
741 aloop
= aloop
->inner
;
744 while (aloop
!= NULL
&& aloop
->next
== NULL
)
745 aloop
= loop_outer (aloop
);
753 *loop
= this->next ();
757 loop_iterator::~loop_iterator ()
759 this->to_visit
.release ();
762 #define FOR_EACH_LOOP(LOOP, FLAGS) \
763 for (loop_iterator li(cfun, &(LOOP), FLAGS); \
767 #define FOR_EACH_LOOP_FN(FN, LOOP, FLAGS) \
768 for (loop_iterator li(fn, &(LOOP), FLAGS); \
772 /* The properties of the target. */
773 struct target_cfgloop
{
774 /* Number of available registers. */
775 unsigned x_target_avail_regs
;
777 /* Number of available registers that are call-clobbered. */
778 unsigned x_target_clobbered_regs
;
780 /* Number of registers reserved for temporary expressions. */
781 unsigned x_target_res_regs
;
783 /* The cost for register when there still is some reserve, but we are
784 approaching the number of available registers. */
785 unsigned x_target_reg_cost
[2];
787 /* The cost for register when we need to spill. */
788 unsigned x_target_spill_cost
[2];
791 extern struct target_cfgloop default_target_cfgloop
;
792 #if SWITCHABLE_TARGET
793 extern struct target_cfgloop
*this_target_cfgloop
;
795 #define this_target_cfgloop (&default_target_cfgloop)
798 #define target_avail_regs \
799 (this_target_cfgloop->x_target_avail_regs)
800 #define target_clobbered_regs \
801 (this_target_cfgloop->x_target_clobbered_regs)
802 #define target_res_regs \
803 (this_target_cfgloop->x_target_res_regs)
804 #define target_reg_cost \
805 (this_target_cfgloop->x_target_reg_cost)
806 #define target_spill_cost \
807 (this_target_cfgloop->x_target_spill_cost)
809 /* Register pressure estimation for induction variable optimizations & loop
811 extern unsigned estimate_reg_pressure_cost (unsigned, unsigned, bool, bool);
812 extern void init_set_costs (void);
814 /* Loop optimizer initialization. */
815 extern void loop_optimizer_init (unsigned);
816 extern void loop_optimizer_finalize (function
*);
818 loop_optimizer_finalize ()
820 loop_optimizer_finalize (cfun
);
823 /* Optimization passes. */
826 UAP_UNROLL
= 1, /* Enables unrolling of loops if it seems profitable. */
827 UAP_UNROLL_ALL
= 2 /* Enables unrolling of all loops. */
830 extern void doloop_optimize_loops (void);
831 extern void move_loop_invariants (void);
832 extern vec
<basic_block
> get_loop_hot_path (const struct loop
*loop
);
834 /* Returns the outermost loop of the loop nest that contains LOOP.*/
835 static inline struct loop
*
836 loop_outermost (struct loop
*loop
)
838 unsigned n
= vec_safe_length (loop
->superloops
);
843 return (*loop
->superloops
)[1];
846 extern void record_niter_bound (struct loop
*, const widest_int
&, bool, bool);
847 extern HOST_WIDE_INT
get_estimated_loop_iterations_int (struct loop
*);
848 extern HOST_WIDE_INT
get_max_loop_iterations_int (const struct loop
*);
849 extern HOST_WIDE_INT
get_likely_max_loop_iterations_int (struct loop
*);
850 extern bool get_estimated_loop_iterations (struct loop
*loop
, widest_int
*nit
);
851 extern bool get_max_loop_iterations (const struct loop
*loop
, widest_int
*nit
);
852 extern bool get_likely_max_loop_iterations (struct loop
*loop
, widest_int
*nit
);
853 extern int bb_loop_depth (const_basic_block
);
855 /* Converts VAL to widest_int. */
857 static inline widest_int
858 gcov_type_to_wide_int (gcov_type val
)
862 a
[0] = (unsigned HOST_WIDE_INT
) val
;
863 /* If HOST_BITS_PER_WIDE_INT == HOST_BITS_PER_WIDEST_INT, avoid shifting by
865 val
>>= HOST_BITS_PER_WIDE_INT
- 1;
867 a
[1] = (unsigned HOST_WIDE_INT
) val
;
869 return widest_int::from_array (a
, 2);
871 #endif /* GCC_CFGLOOP_H */