Implement -(a * const) -> a * -const.

[r15897]

diff --git a/ir/ir/iropt.c b/ir/ir/iropt.c
index 724a634..9b22543 100644 (file)
--- a/ir/ir/iropt.c
+++ b/ir/ir/iropt.c
@@ -3186,6 +3186,20 @@ static ir_node *transform_node_Minus(ir_node *n) {
                return n;
        }
 
+       if (is_Mul(a)) { /* -(a * const) -> a * -const */
+               ir_node *mul_l = get_Mul_left(a);
+               ir_node *mul_r = get_Mul_right(a);
+               if (is_Const(mul_r)) {
+                       tarval   *tv    = tarval_neg(get_Const_tarval(mul_r));
+                       ir_node  *cnst  = new_Const(mode, tv);
+                       dbg_info *dbg   = get_irn_dbg_info(a);
+                       ir_graph *irg   = current_ir_graph;
+                       ir_node  *block = get_nodes_block(a);
+                       n = new_rd_Mul(dbg, irg, block, mul_l, cnst, mode);
+                       return n;
+               }
+       }
+
        return n;
 }  /* transform_node_Minus */