re PR tree-optimization/59334 (r205486 caused many failures)

2013-11-29  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/59334
	* tree-ssa-dce.c (eliminate_unnecessary_stmts): Fix bug
	in previous commit.

From-SVN: r205515

gcc/ChangeLog

+2013-11-29  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/59334
+	* tree-ssa-dce.c (eliminate_unnecessary_stmts): Fix bug
+	in previous commit.
+
 2013-11-29  Jakub Jelinek  <jakub@redhat.com>
 	    Richard Biener  <rguenther@suse.de>
 

gcc/tree-ssa-dce.c

@@ -1200,7 +1200,8 @@ eliminate_unnecessary_stmts (void)
 	      if (TREE_CODE (ptr) == SSA_NAME)
 		{
 		  gimple def_stmt = SSA_NAME_DEF_STMT (ptr);
-		  if (!gimple_plf (def_stmt, STMT_NECESSARY))
+		  if (!gimple_nop_p (def_stmt)
+		      && !gimple_plf (def_stmt, STMT_NECESSARY))
 		    gimple_set_plf (stmt, STMT_NECESSARY, false);
 		}
 	    }