X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fir%2Firopt.c;h=093b1f3f4b32f0bcdb75d4ae00a387d0c73e5cc0;hb=f9138cf5219d2b9f69949dcc1fd7258304f83ced;hp=ad79fce7250255dde564a3a2deecee85fa4a0c9e;hpb=055909393f5f1ae98f9f2a33e0fa39326d9d7393;p=libfirm

diff --git a/ir/ir/iropt.c b/ir/ir/iropt.c
index ad79fce72..093b1f3f4 100644
--- a/ir/ir/iropt.c
+++ b/ir/ir/iropt.c
@@ -1,25 +1,32 @@
 /*
- * Project:     libFIRM
- * File name:   ir/ir/iropt.c
- * Purpose:     iropt --- optimizations intertwined with IR construction.
- * Author:      Christian Schaefer
- * Modified by: Goetz Lindenmaier, Michael Beck
- * Created:
- * CVS-ID:      $Id$
- * Copyright:   (c) 1998-2006 Universität Karlsruhe
- * Licence:     This file protected by GPL -  GNU GENERAL PUBLIC LICENSE.
+ * Copyright (C) 1995-2007 University of Karlsruhe.  All right reserved.
+ *
+ * This file is part of libFirm.
+ *
+ * This file may be distributed and/or modified under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation and appearing in the file LICENSE.GPL included in the
+ * packaging of this file.
+ *
+ * Licensees holding valid libFirm Professional Edition licenses may use
+ * this file in accordance with the libFirm Commercial License.
+ * Agreement provided with the Software.
+ *
+ * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
+ * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE.
  */
 
+/**
+ * @file
+ * @brief   iropt --- optimizations intertwined with IR construction.
+ * @author  Christian Schaefer, Goetz Lindenmaier, Michael Beck
+ * @version $Id$
+ */
 #ifdef HAVE_CONFIG_H
 # include "config.h"
 #endif
 
-#ifdef HAVE_ALLOCA_H
-#include <alloca.h>
-#endif
-#ifdef HAVE_MALLOC_H
-#include <malloc.h>
-#endif
 #ifdef HAVE_STRING_H
 #include <string.h>
 #endif
@@ -43,6 +50,7 @@
 #include "opt_polymorphy.h"
 #include "opt_confirms.h"
 #include "irtools.h"
+#include "xmalloc.h"
 
 /* Make types visible to allow most efficient access */
 #include "entity_t.h"
@@ -3659,9 +3667,17 @@ ir_node *identify_remember(pset *value_table, ir_node *n) {
 		if (is_op_commutative(get_irn_op(n))) {
 			ir_node *l = get_binop_left(n);
 			ir_node *r = get_binop_right(n);
-
-			/* for commutative operators perform  a OP b == b OP a */
-			if (l > r) {
+			int l_idx = get_irn_idx(l);
+			int r_idx = get_irn_idx(r);
+
+			/* For commutative operators perform  a OP b == b OP a but keep
+			   constants on the RIGHT side. This helps greatly in some optimizations.
+			   Moreover we use the idx number to make the form deterministic. */
+			if (is_irn_constlike(l))
+				l_idx = -l_idx;
+			if (is_irn_constlike(r))
+				r_idx = -r_idx;
+			if (l_idx < r_idx) {
 				set_binop_left(n, r);
 				set_binop_right(n, l);
 			}
@@ -3669,7 +3685,7 @@ ir_node *identify_remember(pset *value_table, ir_node *n) {
 	}
 
 	/* lookup or insert in hash table with given hash key. */
-	o = pset_insert (value_table, n, ir_node_hash (n));
+	o = pset_insert(value_table, n, ir_node_hash(n));
 
 	if (o != n) {
 		DBG_OPT_CSE(n, o);