contrib/gcc/tree-ssa-loop-ivcanon.c

33    loop completely, we do it right here to expose the optimization
73 create_canonical_iv (struct loop *loop, edge exit, tree niter)
82       fprintf (dump_file, "Added canonical iv to loop %d, ", loop->num);
104 	     NULL_TREE, loop,
117 tree_num_loop_insns (struct loop *loop)
119   basic_block *body = get_loop_body (loop);
123   for (i = 0; i < loop->num_nodes; i++)
131 /* Estimate number of insns of completely unrolled loop.  We assume
132    that the size of the unrolled loop is decreased in the
142    NINSNS is the number of insns in the loop before unrolling.
143    NUNROLL is the number of times the loop is unrolled.  */
158    loop tree.  UL determines which loops we are allowed to unroll.
159    EXIT is the exit of the loop that should be eliminated.  */
163 			    struct loop *loop,
170   if (loop->inner)
186       ninsns = tree_num_loop_insns (loop);
206 		fprintf (dump_file, "Not unrolling loop %d:\n", loop->num);
239       if (!tree_duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop),
264     fprintf (dump_file, "Unrolled loop %d completely.\n", loop->num);
272    to determine the number of iterations of a loop by direct evaluation.
276 canonicalize_loop_induction_variables (struct loops *loops, struct loop *loop,
283   niter = number_of_iterations_in_loop (loop);
286       exit = loop->single_exit;
287       if (!just_once_each_iteration_p (loop, exit->src))
292 	 condition, not of the loop latch edge).  */
298       /* If the loop has more than one exit, try checking all of them
300       if (!loop->single_exit)
301 	niter = find_loop_niter (loop, &exit);
307 	niter = find_loop_niter_by_eval (loop, &exit);
316       fprintf (dump_file, "Loop %d iterates ", loop->num);
321   if (try_unroll_loop_completely (loops, loop, exit, niter, ul))
325     create_canonical_iv (loop, exit, niter);
337   struct loop *loop;
342       loop = loops->parray[i];
344       if (loop)
345 	changed |= canonicalize_loop_induction_variables (loops, loop,
367   struct loop *loop;
373       loop = loops->parray[i];
375       if (!loop)
378       if (may_increase_size && maybe_hot_bb_p (loop->header))
382       changed |= canonicalize_loop_induction_variables (loops, loop,
399 empty_loop_p (struct loop *loop)
409   /* If the loop has multiple exits, it is too hard for us to handle.
411      whether the loop is not infinite.  */
412   exit = single_dom_exit (loop);
416   /* The loop must be finite.  */
417   if (!number_of_iterations_exit (loop, exit, &niter, false))
420   /* Values of all loop exit phi nodes must be invariants.  */
428       if (!expr_invariant_in_loop_p (loop, def))
434   body = get_loop_body (loop);
435   for (i = 0; i < loop->num_nodes; i++)
494 remove_empty_loop (struct loop *loop)
496   edge exit = single_dom_exit (loop), non_exit;
523      and FREQ_H is the frequency of the loop header.
525   freq_h = loop->header->frequency;
526   freq_in = EDGE_FREQUENCY (loop_preheader_edge (loop));
529       body = get_loop_body_in_dom_order (loop);
530       for (n_before = 1; n_before <= loop->num_nodes; n_before++)
534       scale_bbs_frequencies_int (body + n_before, loop->num_nodes - n_before,
548 try_remove_empty_loop (struct loop *loop, bool *changed)
551   struct loop *sub;
554   for (sub = loop->inner; sub; sub = sub->next)
557   if (nonempty_subloop || !empty_loop_p (loop))
560   remove_empty_loop (loop);
571   struct loop *loop;
573   for (loop = loops->tree_root->inner; loop; loop = loop->next)
574     try_remove_empty_loop (loop, &changed);