value_of() is now a simple wrapper around a function pointer. This allows...

value_of() is now a simple wrapper around a function pointer. This allows phases to have its own value_of semantic (needed for the combo algorithm for instance).

set_value_of_func() can be used to set a new semantic or restore the default behavior.

[r20462]

ir/ir/iropt.c

@@ -53,6 +53,25 @@
 /* Make types visible to allow most efficient access */
 #include "entity_t.h"
 
+/**
+ * Returns the tarval of a Const node or tarval_bad for all other nodes.
+ */
+static tarval *default_value_of(const ir_node *n) {
+	if (is_Const(n))
+		return get_Const_tarval(n); /* might return tarval_bad */
+	else
+		return tarval_bad;
+}
+
+value_of_func value_of_ptr = default_value_of;
+
+void set_value_of_func(value_of_func func) {
+	if (func != NULL)
+		value_of_ptr = func;
+	else
+		value_of_ptr = default_value_of;
+}
+
 /**
  * Return the value of a Constant.
  */
@@ -4693,6 +4712,7 @@ static ir_node *transform_node_shift(ir_node *n) {
 	ir_node *left, *right;
 	ir_mode *mode;
 	tarval *tv1, *tv2, *res;
+	ir_node *in[2], *irn, *block;
 
 	left = get_binop_left(n);
 
@@ -4739,7 +4759,7 @@ static ir_node *transform_node_shift(ir_node *n) {
 	}
 
 	/* ok, we can replace it */
-	ir_node *in[2], *irn, *block = get_irn_n(n, -1);
+	block = get_nodes_block(n);
 
 	in[0] = get_binop_left(left);
 	in[1] = new_r_Const(current_ir_graph, block, get_tarval_mode(res), res);

ir/ir/iropt_t.h

@@ -82,14 +82,28 @@ ir_node *optimize_node(ir_node *n);
 ir_node *optimize_in_place_2(ir_node *n);
 
 /**
- * Returns the tarval of a Const node or tarval_bad for all other nodes.
+ * The value_of operation.
+ * This operation returns for every IR node an associated tarval if existing,
+ * returning tarval_bad otherwise.
+ * No calculations are done here, just a lookup.
+ */
+typedef tarval *(*value_of_func)(const ir_node *self);
+
+extern value_of_func value_of_ptr;
+
+/**
+ * Set a new value_of function.
+ *
+ * @param func  the function, NULL restores the default behavior
+ */
+void set_value_of_func(value_of_func func);
+
+/**
+ * Returns the associated tarval of a node.
  */
 static INLINE tarval *
-value_of(ir_node *n) {
-	if ((n != NULL) && is_Const(n))
-		return get_Const_tarval(n); /* might return tarval_bad */
-	else
-		return tarval_bad;
+value_of(const ir_node *n) {
+	return value_of_ptr(n);
 }
 
 /**