* basic-block.h (flow_delete_block_noexpunge): Declare.

	(expunge_block_nocompact): Declare.
	* cfg.c (expunge_block_nocompact): Split out from ...
	(expunge_block): ... here.
	* cfgrtl.c (can_delete_label_p): Don't use exception_handler_labels.
	(flow_delete_block_noexpunge): Split out from ...
	(flow_delete_block): ... here.
	* cfgcleanup.c (delete_unreachable_blocks): Compact while
	removing dead blocks.
	* except.c (exception_handler_labels): Remove.
	(exception_handler_label_map): New.
	(struct eh_region): Add aka member.
	(mark_ehl_map_entry, mark_ehl_map, free_region): New.
	(ehl_hash, ehl_eq, ehl_free, add_ehl_entry): New.
	(for_each_eh_label, for_each_eh_label_1): New.
	(init_eh): Register exception_handler_label_map.
	(free_eh_status): Use free_region.
	(find_exception_handler_labels): Use the map, not the list.
	(remove_exception_handler_label): Likewise.
	(maybe_remove_eh_handler): Likewise.
	(remove_eh_handler): Use the region aka bitmap.
	* except.h (exception_handler_labels): Remove.
	(for_each_eh_label): Declare.
	* jump.c (rebuild_jump_labels): Don't check exception_handler_labels.
	* loop.c (invalidate_loops_containing_label): New.
	(find_and_verify_loops): Use it.  Use for_each_eh_label.
	* sched-rgn.c (is_cfg_nonregular): Use
	current_function_has_exception_handlers.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@52100 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 18 insertions, 7 deletions

diff --git a/gcc/cfgcleanup.c b/gcc/cfgcleanup.c
index b6a7f0cc4ea..74a2256b5e2 100644
--- a/gcc/cfgcleanup.c
+++ b/gcc/cfgcleanup.c
@@ -1,6 +1,6 @@
 /* Control flow optimization code for GNU compiler.
    Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
-   1999, 2000, 2001 Free Software Foundation, Inc.
+   1999, 2000, 2001, 2002 Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -1751,22 +1751,33 @@ try_optimize_cfg (mode)
 static bool
 delete_unreachable_blocks ()
 {
-  int i;
+  int i, j;
   bool changed = false;
 
   find_unreachable_blocks ();
 
-  /* Delete all unreachable basic blocks.  Count down so that we
-     don't interfere with the block renumbering that happens in
-     flow_delete_block.  */
+  /* Delete all unreachable basic blocks.  Do compaction concurrently,
+     as otherwise we can wind up with O(N^2) behaviour here when we 
+     have oodles of dead code.  */
 
-  for (i = n_basic_blocks - 1; i >= 0; --i)
+  for (i = j = 0; i < n_basic_blocks; ++i)
     {
       basic_block b = BASIC_BLOCK (i);
 
       if (!(b->flags & BB_REACHABLE))
-	flow_delete_block (b), changed = true;
+	{
+	  flow_delete_block_noexpunge (b);
+	  expunge_block_nocompact (b);
+	  changed = true;
+	}
+      else
+	{
+	  BASIC_BLOCK (j) = b;
+	  b->index = j++;
+	}
     }
+  n_basic_blocks = j;
+  basic_block_info->num_elements = j;
 
   if (changed)
     tidy_fallthru_edges ();