From: Matthias Braun <matze@braunis.de>
Date: Mon, 9 Aug 2010 14:53:08 +0000 (+0000)
Subject: improved normalisation of not+eor nodes
X-Git-Url: http://nsz.repo.hu/git/?a=commitdiff_plain;h=641834c2a29c31d62989205e016c7b65d8231777;p=libfirm

improved normalisation of not+eor nodes

[r27913]
---

diff --git a/ir/ir/iropt.c b/ir/ir/iropt.c
index ce18fccc7..7fe3ceaf0 100644
--- a/ir/ir/iropt.c
+++ b/ir/ir/iropt.c
@@ -3645,23 +3645,28 @@ static ir_node *transform_node_Eor(ir_node *n)
 		n = new_rd_Const(get_irn_dbg_info(n), current_ir_graph,
 		                 get_mode_null(mode));
 		DBG_OPT_ALGSIM0(oldn, n, FS_OPT_EOR_A_A);
-	} else if (is_Const(b)) {
-		if (is_Not(a)) { /* ~x ^ const -> x ^ ~const */
-			ir_node  *cnst   = new_Const(tarval_not(get_Const_tarval(b)));
-			ir_node  *not_op = get_Not_op(a);
-			dbg_info *dbg    = get_irn_dbg_info(n);
-			ir_node  *block  = get_nodes_block(n);
-			ir_mode  *mode   = get_irn_mode(n);
-			n = new_rd_Eor(dbg, block, not_op, cnst, mode);
-			return n;
-		} else if (is_Const_all_one(b)) { /* x ^ 1...1 -> ~1 */
-			n = new_r_Not(get_nodes_block(n), a, mode);
-			DBG_OPT_ALGSIM0(oldn, n, FS_OPT_EOR_TO_NOT);
-		}
-	} else {
-		n = transform_bitwise_distributive(n, transform_node_Eor);
+		return n;
+	}
+
+	/* normalize not nodes... ~a ^ b => a ^ ~b */
+	if (is_Not(a)) {
+		dbg_info *dbg      = get_irn_dbg_info(n);
+		ir_node  *block    = get_nodes_block(n);
+		ir_node  *new_not  = new_rd_Not(dbg, block, b, mode);
+		ir_node  *new_left = get_Not_op(a);
+		n = new_rd_Eor(dbg, block, new_left, new_not, mode);
+		DBG_OPT_ALGSIM0(oldn, n, FS_OPT_EOR_TO_NOT);
+		return n;
+	}
+
+	/* x ^ 1...1 -> ~1 */
+	if (is_Const(b) && is_Const_all_one(b)) {
+		n = new_r_Not(get_nodes_block(n), a, mode);
+		DBG_OPT_ALGSIM0(oldn, n, FS_OPT_EOR_TO_NOT);
+		return n;
 	}
 
+	n = transform_bitwise_distributive(n, transform_node_Eor);
 	return n;
 }  /* transform_node_Eor */
 
@@ -3687,18 +3692,18 @@ static ir_node *transform_node_Not(ir_node *n)
 			return n;
 		}
 	}
+
+	/* normalize ~(a ^ b) => a ^ ~b */
 	if (is_Eor(a)) {
-		ir_node *eor_b = get_Eor_right(a);
-		if (is_Const(eor_b)) { /* ~(x ^ const) -> x ^ ~const */
-			ir_node  *cnst  = new_Const(tarval_not(get_Const_tarval(eor_b)));
-			ir_node  *eor_a = get_Eor_left(a);
-			dbg_info *dbg   = get_irn_dbg_info(n);
-			ir_node  *block = get_nodes_block(n);
-			ir_mode  *mode  = get_irn_mode(n);
-			n = new_rd_Eor(dbg, block, eor_a, cnst, mode);
-			return n;
-		}
+		dbg_info *dbg       = get_irn_dbg_info(n);
+		ir_node  *block     = get_nodes_block(n);
+		ir_node  *eor_right = get_Eor_right(a);
+		ir_node  *eor_left  = get_Eor_left(a);
+		eor_right = new_rd_Not(dbg, block, eor_right, mode);
+		n = new_rd_Eor(dbg, block, eor_left, eor_right, mode);
+		return n;
 	}
+
 	if (get_mode_arithmetic(mode) == irma_twos_complement) {
 		if (is_Minus(a)) { /* ~-x -> x + -1 */
 			dbg_info *dbg   = get_irn_dbg_info(n);