Fixed opt/fehler193.c.

[libfirm] / ir / be / ia32 / ia32_address_mode.c

diff --git a/ir/be/ia32/ia32_address_mode.c b/ir/be/ia32/ia32_address_mode.c
index 5e2aea2..2b4ff29 100644 (file)
--- a/ir/be/ia32/ia32_address_mode.c
+++ b/ir/be/ia32/ia32_address_mode.c
@@ -418,7 +418,8 @@ int ia32_is_non_address_mode_node(ir_node const *node)
 }
 
 /**
- * Check if a given value is last used (i.e. die after) the block of some other node.
+ * Check if a given value is last used (i.e. die after) the block of some
+ * other node.
  */
 static int value_last_used_here(be_lv_t *lv, ir_node *here, ir_node *value)
 {
@@ -441,6 +442,12 @@ static int value_last_used_here(be_lv_t *lv, ir_node *here, ir_node *value)
        return 1;
 }
 
+static bool simple_is_immediate(const ir_node *node)
+{
+       int symconsts = 0;
+       return do_is_immediate(node, &symconsts, false);
+}
+
 /**
  * Walker: mark those nodes that cannot be part of an address mode because
  * their value must be accessed through a register
@@ -486,12 +493,17 @@ static void mark_non_address_nodes(ir_node *node, void *env)
                left  = get_binop_left(node);
                right = get_binop_right(node);
 
-               /* Fold AM if any of the two operands does not die here.  This duplicates
+               /* if any of the operands is an immediate then this will not
+                * increase register pressure */
+               if (simple_is_immediate(left) || simple_is_immediate(right))
+                       return;
+
+               /* Fold AM if any of the two operands does not die here. This duplicates
                 * an addition and has the same register pressure for the case that only
                 * one operand dies, but is faster (on Pentium 4).
                 * && instead of || only folds AM if both operands do not die here */
                if (!value_last_used_here(lv, node, left) ||
-                               !value_last_used_here(lv, node, right)) {
+                   !value_last_used_here(lv, node, right)) {
                        return;
                }