re PR tree-optimization/57318 (optimizer takes several seconds on nested loops)

2013-05-21  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/57318
	* tree-ssa-loop-ivcanon.c (tree_estimate_loop_size): Do not
	estimate stmts with side-effects as likely eliminated.

From-SVN: r199140

gcc/ChangeLog

 2013-05-21  Richard Biener  <rguenther@suse.de>
 
+	PR tree-optimization/57318
+	* tree-ssa-loop-ivcanon.c (tree_estimate_loop_size): Do not
+	estimate stmts with side-effects as likely eliminated.
+
+2013-05-21  Richard Biener  <rguenther@suse.de>
+
 	PR tree-optimization/57330
 	* cgraph.c (cgraph_redirect_edge_call_stmt_to_callee): Properly
 	preserve the call stmts fntype.

gcc/tree-ssa-loop-ivcanon.c

@@ -257,8 +257,10 @@ tree_estimate_loop_size (struct loop *loop, edge exit, edge edge_to_cancel, stru
 
 	  /* Look for reasons why we might optimize this stmt away. */
 
+	  if (gimple_has_side_effects (stmt))
+	    ;
 	  /* Exit conditional.  */
-	  if (exit && body[i] == exit->src
+	  else if (exit && body[i] == exit->src
 		   && stmt == last_stmt (exit->src))
 	    {
 	      if (dump_file && (dump_flags & TDF_DETAILS))