namespace ir_builder {
-ir_expression *expr(ir_expression_operation op, ir_rvalue *a, ir_rvalue *b);
-ir_expression *add(ir_rvalue *a, ir_rvalue *b);
-ir_expression *sub(ir_rvalue *a, ir_rvalue *b);
-ir_expression *mul(ir_rvalue *a, ir_rvalue *b);
-ir_expression *dot(ir_rvalue *a, ir_rvalue *b);
-ir_expression *saturate(ir_rvalue *a);
+/**
+ * This little class exists to let the helper expression generators
+ * take either an ir_rvalue * or an ir_variable * to be automatically
+ * dereferenced, while still providing compile-time type checking.
+ *
+ * You don't have to explicitly call the constructor -- C++ will see
+ * that you passed an ir_variable, and silently call the
+ * operand(ir_variable *var) constructor behind your back.
+ */
+class operand {
+public:
+ operand(ir_rvalue *val)
+ : val(val)
+ {
+ }
+
+ operand(ir_variable *var)
+ {
+ void *mem_ctx = ralloc_parent(var);
+ val = new(mem_ctx) ir_dereference_variable(var);
+ }
+
+ ir_rvalue *val;
+};
+
+/** Automatic generator for ir_dereference_variable on assignment LHS.
+ *
+ * \sa operand
+ */
+class deref {
+public:
+ deref(ir_dereference *val)
+ : val(val)
+ {
+ }
+
+ deref(ir_variable *var)
+ {
+ void *mem_ctx = ralloc_parent(var);
+ val = new(mem_ctx) ir_dereference_variable(var);
+ }
+
+
+ ir_dereference *val;
+};
+
+class ir_factory {
+public:
+ void emit(ir_instruction *ir);
+ ir_variable *make_temp(const glsl_type *type, const char *name);
+
+ exec_list *instructions;
+ void *mem_ctx;
+};
+
+ir_assignment *assign(deref lhs, operand rhs);
+ir_assignment *assign(deref lhs, operand rhs, int writemask);
+
+ir_expression *expr(ir_expression_operation op, operand a);
+ir_expression *expr(ir_expression_operation op, operand a, operand b);
+ir_expression *add(operand a, operand b);
+ir_expression *sub(operand a, operand b);
+ir_expression *mul(operand a, operand b);
+ir_expression *dot(operand a, operand b);
+ir_expression *saturate(operand a);
+
+/**
+ * Swizzle away later components, but preserve the ordering.
+ */
+ir_swizzle *swizzle_for_size(operand a, unsigned components);
+
+ir_swizzle *swizzle_xxxx(operand a);
+ir_swizzle *swizzle_yyyy(operand a);
+ir_swizzle *swizzle_zzzz(operand a);
+ir_swizzle *swizzle_wwww(operand a);
+ir_swizzle *swizzle_x(operand a);
+ir_swizzle *swizzle_y(operand a);
+ir_swizzle *swizzle_z(operand a);
+ir_swizzle *swizzle_w(operand a);
+ir_swizzle *swizzle_xy(operand a);
+ir_swizzle *swizzle_xyz(operand a);
+ir_swizzle *swizzle_xyzw(operand a);
} /* namespace ir_builder */