gcc/gcc/cfgloop.h

1 /* Natural loop functions
59 /* The structure describing a bound on number of iterations of a loop.  */
74   /* True if the statement will cause the loop to be leaved the (at most)
83 /* Description of the loop exit.  */
89   /* Previous and next exit in the list of the exits of the loop.  */
106 typedef struct loop *loop_p;
119 /* Structure to hold information for each natural loop.  */
120 struct GTY ((chain_next ("%h.next"))) loop {
124   /* Number of loop insns.  */
127   /* Basic block of loop header.  */
130   /* Basic block of loop latch.  */
133   /* For loop unrolling/peeling decision.  */
139   /* Number of blocks contained within the loop.  */
142   /* Superloops of the loop, starting with the outermost loop.  */
145   /* The first inner (child) loop or NULL if innermost loop.  */
146   struct loop *inner;
148   /* Link to the next (sibling) loop.  */
149   struct loop *next;
154   /* The number of times the latch of the loop is executed.  This can be an
175   /* True if the loop can be parallel.  */
178   /* True if -Waggressive-loop-optimizations warned about this loop
189      of the loop can be safely evaluated concurrently.  */
192   /* True if this loop should never be vectorized.  */
195   /* True if we should try harder to vectorize this loop.  */
198   /* For SIMD loops, this is a unique identifier of the loop, referenced
203   /* Upper bound on number of iterations of a loop.  */
206   /* Head of the cyclic list of the exits of the loop.  */
212   /* For sanity checking during loop fixup we record here the former
213      loop header for loops marked for removal.  Note that this prevents
219 /* Flags for state of loop structure.  */
244   /* Maps edges to the list of their descriptions as loop exits.  Edges
249   /* Pointer to root of loop hierarchy tree.  */
250   struct loop *tree_root;
260 			     void (*)(const struct loop *, FILE *, int), int);
261 extern void flow_loop_dump (const struct loop *, FILE *,
262 			    void (*)(const struct loop *, FILE *, int), int);
263 struct loop *alloc_loop (void);
264 extern void flow_loop_free (struct loop *);
265 int flow_loop_nodes_find (basic_block, struct loop *);
273 extern void flow_loop_tree_node_add (struct loop *, struct loop *);
274 extern void flow_loop_tree_node_remove (struct loop *);
275 extern bool flow_loop_nested_p	(const struct loop *, const struct loop *);
276 extern bool flow_bb_inside_loop_p (const struct loop *, const_basic_block);
277 extern struct loop * find_common_loop (struct loop *, struct loop *);
278 struct loop *superloop_at_depth (struct loop *, unsigned);
280 extern int num_loop_insns (const struct loop *);
281 extern int average_num_loop_insns (const struct loop *);
282 extern unsigned get_loop_level (const struct loop *);
283 extern bool loop_exit_edge_p (const struct loop *, const_edge);
284 extern bool loop_exits_to_bb_p (struct loop *, basic_block);
285 extern bool loop_exits_from_bb_p (struct loop *, basic_block);
287 extern location_t get_loop_location (struct loop *loop);
290 extern basic_block *get_loop_body (const struct loop *);
291 extern unsigned get_loop_body_with_size (const struct loop *, basic_block *,
293 extern basic_block *get_loop_body_in_dom_order (const struct loop *);
294 extern basic_block *get_loop_body_in_bfs_order (const struct loop *);
295 extern basic_block *get_loop_body_in_custom_order (const struct loop *,
298 extern vec<edge> get_loop_exit_edges (const struct loop *);
299 extern edge single_exit (const struct loop *);
300 extern edge single_likely_exit (struct loop *loop);
301 extern unsigned num_loop_branches (const struct loop *);
303 extern edge loop_preheader_edge (const struct loop *);
304 extern edge loop_latch_edge (const struct loop *);
306 extern void add_bb_to_loop (basic_block, struct loop *);
309 extern void cancel_loop_tree (struct loop *);
310 extern void delete_loop (struct loop *);
316 extern bool just_once_each_iteration_p (const struct loop *, const_basic_block);
317 gcov_type expected_loop_iterations_unbounded (const struct loop *);
318 extern unsigned expected_loop_iterations (const struct loop *);
367 /* The description of an exit from the loop and of the number of iterations
372   /* The edge out of the loop.  */
379      loop.  */
382   /* True if the loop iterates the constant number of times.  */
391   /* Assumptions under that the loop ends before reaching the latch,
395   /* Condition under that the loop is infinite.  */
404   /* The number of iterations of the loop.  */
408 extern void iv_analysis_loop_init (struct loop *);
415 extern void find_simple_exit (struct loop *, struct niter_desc *);
418 extern struct niter_desc *get_simple_loop_desc (struct loop *loop);
419 extern void free_simple_loop_desc (struct loop *loop);
422 simple_loop_desc (struct loop *loop)
424   return loop->simple_loop_desc;
427 /* Accessors for the loop structures.  */
429 /* Returns the loop with index NUM from FNs loop tree.  */
431 static inline struct loop *
440 loop_depth (const struct loop *loop)
442   return vec_safe_length (loop->superloops);
446    loop.  */
448 static inline struct loop *
449 loop_outer (const struct loop *loop)
451   unsigned n = vec_safe_length (loop->superloops);
456   return (*loop->superloops)[n - 1];
462 loop_has_exit_edges (const struct loop *loop)
464   return loop->exits->next->e != NULL;
480    ones and the fake loop that forms the root of the loop tree).  */
521 /* Flags for loop iteration.  */
525   LI_INCLUDE_ROOT = 1,		/* Include the fake root of the loop tree.  */
535   loop_iterator (loop_p *loop, unsigned flags);
543   /* The index of the actual loop.  */
555       loop_p loop = get_loop (cfun, anum);
556       if (loop)
557 	return loop;
564 loop_iterator::loop_iterator (loop_p *loop, unsigned flags)
566   struct loop *aloop;
574       *loop = NULL;
637   *loop = this->next ();
688 /* Register pressure estimation for induction variable optimizations & loop
706 extern vec<basic_block> get_loop_hot_path (const struct loop *loop);
708 /* Returns the outermost loop of the loop nest that contains LOOP.*/
709 static inline struct loop *
710 loop_outermost (struct loop *loop)
712   unsigned n = vec_safe_length (loop->superloops);
715     return loop;
717   return (*loop->superloops)[1];
720 extern void record_niter_bound (struct loop *, const widest_int &, bool, bool);
721 extern HOST_WIDE_INT get_estimated_loop_iterations_int (struct loop *);
722 extern HOST_WIDE_INT get_max_loop_iterations_int (struct loop *);
723 extern bool get_estimated_loop_iterations (struct loop *loop, widest_int *nit);
724 extern bool get_max_loop_iterations (struct loop *loop, widest_int *nit);