cfgcleanup.c (try_optimize_cfg): Avoid removing ENTRY_BLOCK_PTR.

	* cfgcleanup.c (try_optimize_cfg): Avoid removing ENTRY_BLOCK_PTR.

From-SVN: r121584

gcc/ChangeLog

 2007-02-04  Zdenek Dvorak <dvorakz@suse.cz>
 
+	* cfgcleanup.c (try_optimize_cfg): Avoid removing ENTRY_BLOCK_PTR.
+
+2007-02-04  Zdenek Dvorak <dvorakz@suse.cz>
+
 	* cfgloopmanip.c (loop_delete_branch_edge): Removed.
 	(remove_path): Use can_remove_branch_p and remove_branch instead
 	of loop_delete_branch_edge.
@@ -43,7 +47,7 @@
 	* passes.c (init_optimization_passes): Reindent.
 
 2007-02-04  Jan Hubicka  <jh@suse.cz>
-            Eric Botcazou  <ebotcazou@adacore.com>
+	    Eric Botcazou  <ebotcazou@adacore.com>
 
 	* tree-optimize.c (has_abnormal_outgoing_edge_p): Move to...
 	(execute_fixup_cfg): Break out the abnormal goto code.

gcc/cfgcleanup.c

@@ -1992,7 +1992,7 @@ try_optimize_cfg (int mode)
 	      bool changed_here = false;
 
 	      /* Delete trivially dead basic blocks.  */
-	      while (EDGE_COUNT (b->preds) == 0)
+	      if (EDGE_COUNT (b->preds) == 0)
 		{
 		  c = b->prev_bb;
 		  if (dump_file)
@@ -2002,7 +2002,9 @@ try_optimize_cfg (int mode)
 		  delete_basic_block (b);
 		  if (!(mode & CLEANUP_CFGLAYOUT))
 		    changed = true;
-		  b = c;
+		  /* Avoid trying to remove ENTRY_BLOCK_PTR.  */
+		  b = (c == ENTRY_BLOCK_PTR ? c->next_bb : c);
+		  continue;
 		}
 
 	      /* Remove code labels no longer used.  */