transform Load & 0xFF into Loadzx

[r15389]

diff --git a/ir/be/ia32/ia32_transform.c b/ir/be/ia32/ia32_transform.c
index e315458..018d09f 100644 (file)
--- a/ir/be/ia32/ia32_transform.c
+++ b/ir/be/ia32/ia32_transform.c
@@ -873,7 +873,25 @@ static ir_node *gen_And(ir_node *node) {
        ir_node *op1 = get_And_left(node);
        ir_node *op2 = get_And_right(node);
 
-       assert (! mode_is_float(get_irn_mode(node)));
+       assert(! mode_is_float(get_irn_mode(node)));
+
+       if (is_Const(op2) && is_Load(skip_Proj(op1)) && get_irn_n_edges(op1) == 1) {
+               /* a Load() & Const */
+               tarval *tv = get_Const_tarval(op2);
+               long v = get_tarval_long(tv);
+
+               if (v == 0xFF) {
+                       ir_node *new_op = be_transform_node(op1);
+                       ir_node *load = skip_Proj(new_op);
+                       set_ia32_ls_mode(load, mode_Bu);
+                       return new_op;
+               } else if (v == 0xFFFF) {
+                       ir_node *new_op = be_transform_node(op1);
+                       ir_node *load = skip_Proj(new_op);
+                       set_ia32_ls_mode(load, mode_Hu);
+                       return new_op;
+               }
+       }
        return gen_binop(node, op1, op2, new_rd_ia32_And, 1);
 }