A method and system for converting application code into optimized application code or into execution code suitable for execution on a computation engine with an architecture comprising at least a first and a second level of data memory units are disclosed. In one aspect, the method comprises obtaining application code, the application code comprising data transfer operations between the levels of memory units. The method further comprises converting at least a part of the application code. The converting of application code comprises scheduling of data transfer operations from a first level of memory units to a second level of memory units such that accesses of data accessed multiple times are brought closer together in time than in the original code. The converting of application code further comprises, after the scheduling of the data transfer operations, deciding on layout of the data in the second level of memory units to improve the data layout locality such that data which is accessed closer together in time is also brought closer together in the layout than in the original code.