* doc/loop.texi: Document recording of loop exits.

	* cfgloopmanip.c (loopify, duplicate_loop): Use alloc_loop.
	(update_single_exits_after_duplication,
	update_single_exit_for_duplicated_loop,
	update_single_exit_for_duplicated_loops): Removed.
	(duplicate_loop_to_header_edge): Do not call
	update_single_exits_after_duplication and
	update_single_exit_for_duplicated_loops.
	(loop_version): Do not update single_exit information.
	(fix_loop_structure): Use record_loop_exits instead of
	mark_single_exit_loops.
	* tree-ssa-loop-manip.c (tree_transform_and_unroll_loop): Update
	the lists of loop exits.
	* cfghooks.c (redirect_edge_and_branch, redirect_edge_and_branch_force,
	split_edge, merge_blocks): Update the lists of loop exits.
	* modulo-sched.c (sms_schedule): Pass LOOPS_HAVE_RECORDED_EXITS to
	loop_optimizer_init.
	* loop-init.c (loop_optimizer_init): Call record_loop_exits instead
	of mark_single_exit_loops.
	(loop_optimizer_finalize): Call release_recorded_exits.
	* tree-ssa-loop.c (tree_loop_optimizer_init): Pass
	LOOPS_HAVE_RECORDED_EXITS to loop_optimizer_init.
	* tree-vectorizer.c (slpeel_tree_duplicate_loop_to_edge_cfg): Do not
	update single exit information.
	* lambda-code.c (perfect_nestify): Ditto.
	* cfgloop.c (flow_loop_free): Destroy the list of exits of the loop.
	(mark_single_exit_loops): Removed.
	(alloc_loop, loop_exit_hash, loop_exit_eq, loop_exit_free,
	get_exit_descriptions, rescan_loop_exit, record_loop_exits,
	dump_recorded_exit, dump_recorded_exits, release_recorded_exits): New
	functions.
	(get_loop_exit_edges, single_exit): Use recorded exit lists.
	(add_bb_to_loop, remove_bb_from_loops): Update the lists of loop exits.
	(verify_loop_structure): Verify consistency of the exit lists.
	(flow_loops_find): Use alloc_loop.  Initialize exits hash.
	(set_single_exit): Removed.
	* cfgloop.h (struct loop_exit): New function.
	(struct loop): single_exit_ field replaced by exits field.
	(LOOPS_HAVE_MARKED_SINGLE_EXITS): Replaced by LOOPS_HAVE_RECORDED_EXITS.
	(struct loops): Added exits hash.
	(mark_single_exit_loops, set_single_exit): Declaration removed.
	(release_recorded_exits, record_loop_exits, rescan_loop_exit): Declare.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@120728 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 9 insertions, 81 deletions

diff --git a/gcc/cfgloopmanip.c b/gcc/cfgloopmanip.c
index fd7597e9a12..222bcb3623c 100644
--- a/gcc/cfgloopmanip.c
+++ b/gcc/cfgloopmanip.c
@@ -425,7 +425,7 @@ loopify (edge latch_edge, edge header_edge,
   basic_block *dom_bbs, *body;
   unsigned n_dom_bbs, i;
   sbitmap seen;
-  struct loop *loop = XCNEW (struct loop);
+  struct loop *loop = alloc_loop ();
   struct loop *outer = succ_bb->loop_father->outer;
   int freq;
   gcov_type cnt;
@@ -643,7 +643,7 @@ struct loop *
 duplicate_loop (struct loop *loop, struct loop *target)
 {
   struct loop *cloop;
-  cloop = XCNEW (struct loop);
+  cloop = alloc_loop ();
   place_new_loop (cloop);
 
   /* Mark the new loop as copy of LOOP.  */
@@ -746,65 +746,6 @@ can_duplicate_loop_p (struct loop *loop)
   return ret;
 }
 
-/* The NBBS blocks in BBS will get duplicated and the copies will be placed
-   to LOOP.  Update the single_exit information in superloops of LOOP.  */
-
-static void
-update_single_exits_after_duplication (basic_block *bbs, unsigned nbbs,
-				       struct loop *loop)
-{
-  unsigned i;
-
-  for (i = 0; i < nbbs; i++)
-    bbs[i]->flags |= BB_DUPLICATED;
-
-  for (; loop->outer; loop = loop->outer)
-    {
-      if (!single_exit (loop))
-	continue;
-
-      if (single_exit (loop)->src->flags & BB_DUPLICATED)
-	set_single_exit (loop, NULL);
-    }
-
-  for (i = 0; i < nbbs; i++)
-    bbs[i]->flags &= ~BB_DUPLICATED;
-}
-
-/* Updates single exit information for the copy of LOOP.  */
-
-static void
-update_single_exit_for_duplicated_loop (struct loop *loop)
-{
-  struct loop *copy = loop->copy;
-  basic_block src, dest;
-  edge exit = single_exit (loop);
-
-  if (!exit)
-    return;
-
-  src = get_bb_copy (exit->src);
-  dest = exit->dest;
-  if (dest->flags & BB_DUPLICATED)
-    dest = get_bb_copy (dest);
-
-  exit = find_edge (src, dest);
-  gcc_assert (exit != NULL);
-  set_single_exit (copy, exit);
-}
-
-/* Updates single exit information for copies of ORIG_LOOPS and their subloops.
-   N is the number of the loops in the ORIG_LOOPS array.  */
-
-static void
-update_single_exit_for_duplicated_loops (struct loop *orig_loops[], unsigned n)
-{
-  unsigned i;
-
-  for (i = 0; i < n; i++)
-    update_single_exit_for_duplicated_loop (orig_loops[i]);
-}
-
 /* Sets probability and count of edge E to zero.  The probability and count
    is redistributed evenly to the remaining edges coming from E->src.  */
 
@@ -1018,10 +959,6 @@ duplicate_loop_to_header_edge (struct loop *loop, edge e,
       first_active_latch = latch;
     }
 
-  /* Update the information about single exits.  */
-  if (current_loops->state & LOOPS_HAVE_MARKED_SINGLE_EXITS)
-    update_single_exits_after_duplication (bbs, n, target);
-
   spec_edges[SE_ORIG] = orig;
   spec_edges[SE_LATCH] = latch_edge;
 
@@ -1036,15 +973,6 @@ duplicate_loop_to_header_edge (struct loop *loop, edge e,
 		place_after);
       place_after = new_spec_edges[SE_LATCH]->src;
 
-      if (current_loops->state & LOOPS_HAVE_MARKED_SINGLE_EXITS)
-	{
-	  for (i = 0; i < n; i++)
-	    bbs[i]->flags |= BB_DUPLICATED;
-	  update_single_exit_for_duplicated_loops (orig_loops, n_orig_loops);
-	  for (i = 0; i < n; i++)
-	    bbs[i]->flags &= ~BB_DUPLICATED;
-	}
-
       if (flags & DLTHE_RECORD_COPY_NUMBER)
 	for (i = 0; i < n; i++)
 	  {
@@ -1378,7 +1306,7 @@ loop_version (struct loop *loop,
 	      bool place_after)
 {
   basic_block first_head, second_head;
-  edge entry, latch_edge, exit, true_edge, false_edge;
+  edge entry, latch_edge, true_edge, false_edge;
   int irred_flag;
   struct loop *nloop;
   basic_block cond_bb;
@@ -1425,10 +1353,6 @@ loop_version (struct loop *loop,
 		   false /* Do not redirect all edges.  */,
 		   then_scale, else_scale);
 
-  exit = single_exit (loop);
-  if (exit)
-    set_single_exit (nloop, find_edge (get_bb_copy (exit->src), exit->dest));
-
   /* loopify redirected latch_edge. Update its PENDING_STMTS.  */
   lv_flush_pending_stmts (latch_edge);
 
@@ -1539,8 +1463,12 @@ fix_loop_structure (bitmap changed_bbs)
       bb->aux = NULL;
     }
 
-  if (current_loops->state & LOOPS_HAVE_MARKED_SINGLE_EXITS)
-    mark_single_exit_loops ();
   if (current_loops->state & LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)
     mark_irreducible_loops ();
+
+  if (current_loops->state & LOOPS_HAVE_RECORDED_EXITS)
+    {
+      release_recorded_exits ();
+      record_loop_exits ();
+    }
 }