basic-block.h (flow_delete_block_noexpunge): Declare.

	* 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.

From-SVN: r52100

gcc/ChangeLog

 2002-04-09  Richard Henderson  <rth@redhat.com>
 
+	* 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.
+
+2002-04-09  Richard Henderson  <rth@redhat.com>
+
 	* sbitmap.c (sbitmap_union_of_diff, sbitmap_a_and_b, sbitmap_a_xor_b,
 	sbitmap_a_or_b, sbitmap_a_or_b_and_c, sbitmap_a_and_b_or_c):
 	Do not return changed status.

gcc/basic-block.h

 /* Define control and data flow tables, and regsets.
-   Copyright (C) 1987, 1997, 1998, 1999, 2000, 2001
+   Copyright (C) 1987, 1997, 1998, 1999, 2000, 2001, 2002
    Free Software Foundation, Inc.
 
 This file is part of GCC.
@@ -316,6 +316,7 @@ extern void redirect_edge_pred		PARAMS ((edge, basic_block));
 extern basic_block create_basic_block_structure PARAMS ((int, rtx, rtx, rtx));
 extern basic_block create_basic_block	PARAMS ((int, rtx, rtx));
 extern int flow_delete_block		PARAMS ((basic_block));
+extern int flow_delete_block_noexpunge	PARAMS ((basic_block));
 extern void clear_bb_flags		PARAMS ((void));
 extern void merge_blocks_nomove		PARAMS ((basic_block, basic_block));
 extern void tidy_fallthru_edge		PARAMS ((edge, basic_block,
@@ -637,6 +638,7 @@ extern void debug_regset		PARAMS ((regset));
 extern void allocate_reg_life_data      PARAMS ((void));
 extern void allocate_bb_life_data	PARAMS ((void));
 extern void expunge_block		PARAMS ((basic_block));
+extern void expunge_block_nocompact	PARAMS ((basic_block));
 extern basic_block alloc_block		PARAMS ((void));
 extern void find_unreachable_blocks	PARAMS ((void));
 extern int delete_noop_moves		PARAMS ((rtx));

gcc/cfg.c

@@ -223,6 +223,17 @@ alloc_block ()
 /* Remove block B from the basic block array and compact behind it.  */
 
 void
+expunge_block_nocompact (b)
+     basic_block b;
+{
+  /* Invalidate data to make bughunting easier.  */
+  memset (b, 0, sizeof *b);
+  b->index = -3;
+  b->succ = (edge) first_deleted_block;
+  first_deleted_block = (basic_block) b;
+}
+
+void
 expunge_block (b)
      basic_block b;
 {
@@ -235,13 +246,10 @@ expunge_block (b)
       x->index = i;
     }
 
-  /* Invalidate data to make bughunting easier.  */
-  memset (b, 0, sizeof *b);
-  b->index = -3;
-  basic_block_info->num_elements--;
   n_basic_blocks--;
-  b->succ = (edge) first_deleted_block;
-  first_deleted_block = (basic_block) b;
+  basic_block_info->num_elements--;
+
+  expunge_block_nocompact (b);
 }
 
 /* Create an edge connecting SRC and DST with FLAGS optionally using

gcc/cfgcleanup.c

 /* 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 ();

gcc/cfgrtl.c

 /* Control flow graph manipulation 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.
 
@@ -102,8 +102,7 @@ can_delete_label_p (label)
 	  /* User declared labels must be preserved.  */
 	  && LABEL_NAME (label) == 0
 	  && !in_expr_list_p (forced_labels, label)
-	  && !in_expr_list_p (label_value_list, label)
-	  && !in_expr_list_p (exception_handler_labels, label));
+	  && !in_expr_list_p (label_value_list, label));
 }
 
 /* Delete INSN by patching it out.  Return the next insn.  */
@@ -363,7 +362,7 @@ create_basic_block (index, head, end)
    to post-process the stream to remove empty blocks, loops, ranges, etc.  */
 
 int
-flow_delete_block (b)
+flow_delete_block_noexpunge (b)
      basic_block b;
 {
   int deleted_handler = 0;
@@ -412,6 +411,15 @@ flow_delete_block (b)
   b->pred = NULL;
   b->succ = NULL;
 
+  return deleted_handler;
+}
+
+int
+flow_delete_block (b)
+     basic_block b;
+{
+  int deleted_handler = flow_delete_block_noexpunge (b);
+  
   /* Remove the basic block from the array, and compact behind it.  */
   expunge_block (b);
 

gcc/except.h

 /* Exception Handling interface routines.
-   Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001
+   Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002
    Free Software Foundation, Inc.
    Contributed by Mike Stump <mrs@cygnus.com>.
 
@@ -83,8 +83,9 @@ extern void expand_eh_region_end_throw		PARAMS ((tree));
    destroying an object twice.  */
 extern void expand_eh_region_end_fixup		PARAMS ((tree));
 
-/* A list of labels used for exception handlers.  */
-extern rtx exception_handler_labels;
+/* Invokes CALLBACK for every exception handler label.  Only used by old
+   loop hackery; should not be used by new code.  */
+extern void for_each_eh_label			PARAMS ((void (*) (rtx)));
 
 /* Determine if the given INSN can throw an exception.  */
 extern bool can_throw_internal			PARAMS ((rtx));

gcc/jump.c

@@ -91,13 +91,6 @@ rebuild_jump_labels (f)
   for (insn = forced_labels; insn; insn = XEXP (insn, 1))
     if (GET_CODE (XEXP (insn, 0)) == CODE_LABEL)
       LABEL_NUSES (XEXP (insn, 0))++;
-
-  /* Keep track of labels used for marking handlers for exception
-     regions; they cannot usually be deleted.  */
-
-  for (insn = exception_handler_labels; insn; insn = XEXP (insn, 1))
-    if (GET_CODE (XEXP (insn, 0)) == CODE_LABEL)
-      LABEL_NUSES (XEXP (insn, 0))++;
 }
 
 /* Some old code expects exactly one BARRIER as the NEXT_INSN of a

gcc/loop.c

@@ -235,6 +235,7 @@ FILE *loop_dump_stream;
 
 /* Forward declarations.  */
 
+static void invalidate_loops_containing_label PARAMS ((rtx));
 static void find_and_verify_loops PARAMS ((rtx, struct loops *));
 static void mark_loop_jump PARAMS ((rtx, struct loop *));
 static void prescan_loop PARAMS ((struct loop *));
@@ -2609,6 +2610,17 @@ prescan_loop (loop)
     }
 }
 
+/* Invalidate all loops containing LABEL.  */
+
+static void
+invalidate_loops_containing_label (label)
+     rtx label;
+{
+  struct loop *loop;
+  for (loop = uid_loop[INSN_UID (label)]; loop; loop = loop->outer)
+    loop->invalid = 1;
+}
+
 /* Scan the function looking for loops.  Record the start and end of each loop.
    Also mark as invalid loops any loops that contain a setjmp or are branched
    to from outside the loop.  */
@@ -2695,23 +2707,12 @@ find_and_verify_loops (f, loops)
 
   /* Any loop containing a label used in an initializer must be invalidated,
      because it can be jumped into from anywhere.  */
-
   for (label = forced_labels; label; label = XEXP (label, 1))
-    {
-      for (loop = uid_loop[INSN_UID (XEXP (label, 0))];
-	   loop; loop = loop->outer)
-	loop->invalid = 1;
-    }
+    invalidate_loops_containing_label (XEXP (label, 0));
 
   /* Any loop containing a label used for an exception handler must be
      invalidated, because it can be jumped into from anywhere.  */
-
-  for (label = exception_handler_labels; label; label = XEXP (label, 1))
-    {
-      for (loop = uid_loop[INSN_UID (XEXP (label, 0))];
-	   loop; loop = loop->outer)
-	loop->invalid = 1;
-    }
+  for_each_eh_label (invalidate_loops_containing_label);
 
   /* Now scan all insn's in the function.  If any JUMP_INSN branches into a
      loop that it is not contained within, that loop is marked invalid.
@@ -2735,11 +2736,7 @@ find_and_verify_loops (f, loops)
 	  {
 	    rtx note = find_reg_note (insn, REG_LABEL, NULL_RTX);
 	    if (note)
-	      {
-		for (loop = uid_loop[INSN_UID (XEXP (note, 0))];
-		     loop; loop = loop->outer)
-		  loop->invalid = 1;
-	      }
+	      invalidate_loops_containing_label (XEXP (note, 0));
 	  }
 
 	if (GET_CODE (insn) != JUMP_INSN)

gcc/sched-rgn.c

@@ -339,7 +339,7 @@ is_cfg_nonregular ()
   /* If we have exception handlers, then we consider the cfg not well
      structured.  ?!?  We should be able to handle this now that flow.c
      computes an accurate cfg for EH.  */
-  if (exception_handler_labels)
+  if (current_function_has_exception_handlers ())
     return 1;
 
   /* If we have non-jumping insns which refer to labels, then we consider